Test your knowledge of this week’s health news.
People typically lower their risks of heart disease and premature death far more by gaining fitness than by dropping weight.
Overweight people who ate fewer carbohydrates and increased their fat intake had significant improvements in their cardiovascular disease risk factors.
Nearly one in seven Americans now has diabetes, a record rate. The condition also raises the risk of severe illness after coronavirus infection.
Taking steps to combat acid reflux can help minimize the use of potentially dangerous drugs.
Foods like yogurt, kimchi, sauerkraut and kombucha increased the diversity of gut microbes and led to lower levels of inflammation.
La comunicación celular después del entrenamiento podría ayudar a entender cómo es que los ejercicios de fortalecimiento muscular impactan al tejido adiposo.
A cellular chat after your workout may explain in part why weight training burns fat.
The science behind the idea of restoring the intestinal microbiome to an ancestral state is shaky, skeptics say, and in some cases unethical.
People who regularly do muscle-strengthening exercises are about 20 to 30 percent less likely to become obese over time than people who do not.
As consumption of sugar-laden drinks rose in the 1980s and ’90s, so did colorectal cancer rates among younger adults, a study in nurses found.
Obesity has stalked Marleen Greenleaf, 58, all of her life. Like most people with obesity, she tried diet after diet. But the weight always came back.
With that, she has suffered a lifetime of scorn and stigma. Jeering comments from strangers when she walked down the street. Family members who told her, when she trained for a half-marathon, “I don’t think it’s good for you.”
Then, in 2018, Ms. Greenleaf, an administrator at a charter school in Washington, D.C., participated in a clinical trial for semaglutide, which is a new type of obesity drug, known as incretins.
Over the course of the 68-week study, Ms. Greenleaf slowly lost 40 pounds.
Until then, she had always believed that she could control her weight if she really tried.
“I thought I just needed more motivation,” she said. But when she took semaglutide, she said that “immediately, the urge to eat just dissipated.”
Incretins appear to elicit significant weight loss in most patients, enough to make a real medical and aesthetic difference. But experts hope that the drugs also do something else: change how society feels about people with obesity, and how people with obesity feel about themselves.
If these new drugs allow obesity to be treated like a chronic disease — with medications that must be taken for a lifetime — the thought is that doctors, patients and the public might understand that obesity is truly a medical condition.
“We all believe this drug will change the way we see obesity being treated,” said Dr. Caroline Apovian, an obesity specialist at Brigham and Women’s Hospital. (Dr. Apovian, like most leading obesity researchers, consults for several drug companies. She is on the advisory board of Novo Nordisk, the maker of semaglutide, and is paid for attending advisory board meetings.)
Decades of studies have repeatedly showed that there are powerful biological controls over individual body weights. Identical twins reared apart had nearly identical body weights. Adopted children ended up with body mass indexes like those of their biological parents, not those of their adoptive parents. Metabolism slows as people lose weight, forcing them to regain it.
And yet, obesity “is like having a mark on your forehead,” said Dr. Scott Kahan, chair of the clinical committee for The Obesity Society, a scientific membership organization.
People with obesity are more likely to be passed over for jobs, be paid less than others with the same abilities and training, and be treated poorly by doctors, who spend less time with them and offer fewer preventive services.
But people with obesity haven’t had many places to turn for help. The current obesity drugs lead to an average weight loss of only 5 percent to 10 percent. And because some of these drugs are approved only for limited time frames, the lost pounds almost always come back when the intervention ceases.
According to these studies, incretins seem to be different. Unlike other weight-loss drugs, they are naturally occurring hormones that affect systems central to obesity. The drugs slow stomach emptying, regulate insulin and decrease appetite, with mostly mild to moderate short-term gastrointestinal side effects.
The drugs will not banish obesity or make people truly thin. But people who take them can look and feel very different. For some, the medications lead to weight loss approaching that of bariatric surgery.
If incretins pass the approval process, they might help convince the most important constituency of all — doctors — that obesity is a chronic disease and that it can be treated, said Dr. Robert F. Kushner, an obesity researcher and clinician at Northwestern University. One reason many doctors don’t help patients with obesity is that they don’t know how, Dr. Kushner said. Diets and exercise, the usual nostrums, almost always provide short-term weight loss, at best.
The incretin taken by Ms. Greenleaf, semaglutide, made by Novo Nordisk, is before the Food and Drug Administration, with a decision expected in June. On average it elicited a 15 percent weight loss, but a third of those who took it lost 20 percent or more of their body weight in the study, similar to the amount lost with lap-band bariatric surgery.
Eli Lilly has a similar drug, tirzepatide, which combines two incretins. The company is testing it against semaglutide and hopes that it will be even more powerful.
Dr. Louis J. Aronne, an obesity specialist at Cornell Medical School, said that the combination of semaglutide and another experimental Novo Nordisk drug, cagrilintide, could produce as much as a 25 percent weight loss in a year, an amount like that achieved with sleeve gastrectomy, a popular form of bariatric surgery.
Although more than a half-dozen new hormonal drugs are being tested, Dr. Kushner said, only with long-term use can researchers learn if the new drugs control the many medical consequences of obesity, like diabetes and high blood pressure.
There is also the larger riddle of biological destiny: Are the body’s multiple and redundant systems to maintain body weight so powerful that they will exert control in the end, diminishing the effectiveness of the drugs?
Like other obesity specialists, Dr. Rudolph L. Leibel, a researcher at Columbia University who conducted many of the pivotal studies showing obesity is a disease, deplores society’s bias against his patients. But he has his doubts that perceptions will change with new treatments.
“My guess is that bias will persist and might even be exacerbated by the availability of ‘an easy way out,’” he said.
Dr. Kushner is more hopeful and points to the example of statins, which lower cholesterol and became available in the late 1980s. Until then, doctors could only suggest that patients with high cholesterol cut back on eggs and red meat.
Doctors “embraced statins,” Dr. Kushner said, because they could at last treat this condition. More powerful incretins, he added, could have the same effect on the medical profession.
He is unsure, though, whether patients will accept the disease label. They’ve been conditioned, he said, to believe that their weight is their own fault; all they have to do is eat healthier and exercise more.
When talking with patients, he doesn’t spend 20 minutes trying to convince them that they have a disease. In fact, he deliberately avoids using the word “disease” and instead says “condition” or “problem.”
“I tell them this is a chronic ongoing medical problem, just like diabetes,” he said.
Members of the general public pose a different challenge, Dr. Kushner said. With them, he said, “we may need to use a term like ‘disease.’”
He likens the situation to that of alcoholism or drug addiction, which was once thought to be indicative of a weak will or a moral failing. Researchers have successfully changed the conversation; many people now know that those who abuse alcohol or drugs have a disease and need treatment.
As for Ms. Greenleaf, she wants to take semaglutide again. The pounds crept back when the trial ended.
Obesity, she now realizes, “is not your fault.”
The younger the age at diagnosis for Type 2 diabetes, the higher the risk for Alzheimer’s disease and other forms of dementia years later.
Type 2 diabetes is a chronic, progressive illness that can have devastating complications, including hearing loss, blindness, heart disease, stroke, kidney failure and vascular damage so severe as to require limb amputation. Now a new study underscores the toll that diabetes may take on the brain. It found that Type 2 diabetes is linked to an increased risk for Alzheimer’s disease and other forms of dementia later in life, and the younger the age at which diabetes is diagnosed, the greater the risk.
The findings are especially concerning given the prevalence of diabetes among American adults and rising rates of diabetes in younger people. Once referred to as “adult-onset diabetes” to distinguish it from the immune-related “juvenile-onset” Type 1 disease that begins in childhood, Type 2 diabetes is seen in younger and younger people, largely tied to rising rates of obesity. The Centers for Disease Control and Prevention estimates that more than 34 million American adults have Type 2 diabetes, including more than a quarter of those 65 and over. About 17.5 percent of those aged 45 to 64 have Type 2 disease, as do 4 percent of 18- to 44-year-olds.
“This is an important study from a public health perspective,” said the director of the Yale Diabetes Center, Dr. Silvio Inzucchi, who was not involved in the research. “The complications of diabetes are numerous, but the brain effects are not well studied. Type 2 diabetes is now being diagnosed in children, and at the same time there’s an aging population.”
For the new study, published in JAMA, British researchers tracked diabetes diagnoses among 10,095 men and women who were 35 to 55 at the start of the project, in 1985 to 1988, and free of the disease at the time.
They followed them with clinical examinations every four or five years through 2019. At each examination, the researchers took blood samples to evaluate fasting glucose levels, a measure used to detect diabetes, and recorded self-reported and doctor-diagnosed cases of Type 2 disease.
The researchers also determined dementia cases using British government databases. Over an average follow-up of 32 years, they recorded 1,710 cases of Type 2 diabetes and 639 of dementia.
The researchers calculated that each five-year earlier onset of diabetes was associated with a 24 percent increased risk of dementia. Compared with a person without diabetes, a 70-year-old diagnosed with Type 2 diabetes less than five years earlier had an 11 percent increased risk for dementia. But a diagnosis at age 65 was associated with a 53 percent increased risk of later dementia, and a diagnosis at 60 with a 77 percent increased risk. A person diagnosed with Type 2 at ages 55 to 59 had more than twice the risk of dementia in old age compared with a person in the same age group without diabetes.
The study was observational, so could not prove that diabetes causes dementia. But it was long-running, with a large study population. The researchers controlled for many factors that affect the risk for dementia, including race, education, heart conditions, stroke, smoking and physical activity, and the diabetes-dementia link persisted.
“These are exceptional data,” said Daniel Belsky, an assistant professor of epidemiology at Columbia Mailman School of Public Health who was not involved in the research. “These associations between the timing of onset of diabetes and development of dementia show the importance of a life-course approach to preventing degenerative disease.
“We are an aging population, and the things we fear most are degenerative diseases like dementia, for which we have no cures, no therapies, and very few modifiable pathways to target for prevention,” Dr. Belsky said. “We can’t wait until people are in their 70s.”
Why diabetes would be linked to dementia is unknown. “We can speculate on the mechanisms,” said the study’s senior author, Archana Singh-Manoux, a research professor at INSERM, the French national health institute. “Living a long time with diabetes and having hypoglycemic events is harmful, and there are neurotoxic effects of diabetes as well. The brain uses enormous amounts of glucose, so with insulin resistance, the way the brain uses glucose might be altered” in people with Type 2 diabetes.
Type 2 can be managed and its complications reduced by monitoring blood sugar and conscientiously following a well-designed, personalized program of medication, exercise and diet. Is it possible that such a routine could minimize the risk for dementia later in life?
“With better control, there was less cognitive decline than in those with poor control,” Dr. Singh-Manoux said. “So stick to your medication. Look after your glycemic markers. That’s the message for people who have diabetes.”
Physical activity during pregnancy might have long-lasting benefits for a child’s health, new research suggests.
The lifestyles of soon-to-be mothers and fathers could shape the health of their unborn offspring in lasting ways, according to a surprising new animal study of exercise, diet, genetics and parenthood.
The study found that rodent parents-to-be that fatten on a greasy diet before mating produce offspring with sky-high later risks for metabolic problems. But if the mothers stay active during their pregnancies, those risks disappear.
The study involved mice, not people, but does suggest that when a mother exercises during pregnancy, she may help protect her unborn children against the unhealthy effects of their father’s poor eating habits, as well as her own. The findings add to our growing understanding of the ways in which parents influence children’s long-term health, even before birth, and suggest how physical activity during pregnancy might help to ensure that those impacts are beneficial.
Researchers have known for some time that parents, and especially mothers, begin influencing the health and behavior of their offspring well before conception. Studies involving both animals and people show that mothers with diabetes, obesity, insulin resistance or other metabolic problems before pregnancy tend to have babies with a predisposition to those same conditions as adults, even if the offspring follow healthy lifestyles. Mothers who are lean and physically active during pregnancy, meanwhile, tend to have children who, as adults, are active and metabolically healthy.
A hefty percentage of these differences are a result, no doubt, of nurture, since children readily adopt the diet and exercise habits of their parents. But some proportion of babies’ metabolic futures seem hard-wired, built into them as they develop in the womb, through a process that scientists call metabolic programming.
Metabolic programming is complex and still only partially understood, but involves the inner workings both of the womb and of parental DNA. Some aspects of the environment inside the womb can change, depending on a mother’s health and lifestyle, affecting the development of organs and biological systems in the fetus.
Ditto for parental genetics. The operations of certain of our genes shift in response to our diets, exercise habits, metabolic health and other lifestyle factors. These shifts, which are known as epigenetic changes, become embedded in our DNA and can be passed along to the next generation by mothers or fathers.
In this way, metabolic problems can be inherited, propagating across generations.
But there are hints that physical activity snips this cycle. In past rodent studies, if the soon-to-be parents ran before mating, they typically produced offspring without heightened risks for diabetes or obesity, even if the parents themselves experienced those conditions.
Most of these studies focused their attention on the impacts of the mothers’ health and habits, though. Less has been known about how a father’s metabolic health changes his children’s long-term metabolic prospects and whether a mother’s activities during pregnancy might counter any negative outcomes from a father’s way of life.
So, for the new study, which was published in March in the Journal of Applied Physiology, scientists at the University of Virginia School of Medicine and other institutions first gathered a large group of mice. Some of the animals, male and female, were allowed to gorge on a high-fat, high-calorie diet, inducing obesity and metabolic problems, while others remained on normal chow, at their usual weight.
Next, the mice hooked up, with obese animals of both genders mating with normal-weight mice, so that, in theory, one parent in each pairing could bequeath unhealthy habits and metabolism to the young. A few normal-weight animals without metabolic problems also mated, to produce control offspring.
Finally, some mothers, including the obese, jogged on little running wheels throughout the resulting pregnancies, voluntarily covering up to seven miles a week in the early stages of their three-week gestations.
Afterward, the researchers tracked the metabolic health and underlying genetic activity of the offspring, until they reached adulthood. This second generation ate normal chow and led normal, lab-mouse lives.
Many, though, developed multiple metabolic problems as adults, including obesity, insulin resistance and other disruptions of their blood-sugar control. These conditions were most pronounced in the male children of obese mothers and in both the male and female children born to obese fathers.
Interestingly, the underlying genetics of their conditions differed by parental gender. Mice born to obese mothers displayed unusual activity in a set of genes known to be involved in inflammation. Those born to obese fathers did not.
In other words, the genetic legacies from mothers and fathers “operate through different biological pathways,” says Zhen Yan, a professor of medicine and director of the Center for Skeletal Muscle Research at the University of Virginia School of Medicine, who oversaw the new study.
Perhaps most important, though, when the mothers ran during pregnancy, their children showed almost no undesirable metabolic outcomes as adults, whether the mother or father was obese. These offspring, metabolically and genetically, remained indistinguishable from animals born to healthy parents.
Of course, this was a rodent study and we are not mice, so it is impossible to know if we — as mothers, fathers or offspring — respond similarly to diets and exercise, or if the effects are amplified when both parents are affected. The study also does not show if it is obesity or a high-fat diet that most drives intergenerational harms or what the ideal timing, types and amounts of exercise might be by either mom or dad, to combat those effects.
Dr. Yan says he and his colleagues plan to investigate those questions in future experiments. But already, the current study and other research suggest, he says, that physical activity, before and during pregnancy, and by both the expectant mother and father, “should absolutely be encouraged.”
Medical privacy has become the latest casualty of vaccination efforts, as friends, co-workers and even total strangers ask intrusive questions about personal health conditions.
When Helena Jenkins, 23, recently asked to leave work early for a vaccination appointment, her boss at a Nashville retail store was incredulous.
“Well how did you get that?” he asked.
Ms. Jenkins was embarrassed, but answered truthfully. “Um, my weight,” she stammered, referring to the fact that, in Tennessee, a body mass index of 30 qualified her for vaccination in early March. “I had a moment of ‘ugh,’” she said later. “It made me so uncomfortable, but it didn’t click until afterward that I definitely didn’t have to answer that.”
As public health officials push to get more at-risk people vaccinated, many of the newly qualified are discovering an unwelcome side effect of vaccination: Intrusive questions about their personal health.
The majority of states now have expanded vaccine eligibility to include people with underlying health conditions that put them at risk for complications from Covid-19, such as high blood pressure, a compromised immune system or obesity. As a result, the demographics of the vaccine waiting lines have shifted from mostly older people and now include many seemingly healthy people in their 20s, 30s and 40s. Young vaccine recipients say their friends and co-workers are intensely curious about the appointment process, and as a result, often ignore boundaries about personal health that they never would have crossed in the past. Some of them ask directly: “What health problem allowed you to qualify?”
When Amy Coody, 43, a mental health worker in Montgomery, Ala., told her friends and colleagues she had a vaccine appointment, she was shocked when it felt like people were judging her and assuming she had taken another person’s spot in line. Ms. Coody knows that she looks young and healthy, but she qualifies for two reasons — her work takes her into hospital settings, and she also has an underlying health condition that puts her at high risk.
“The hostility was definitely there,” she said. “They’d be like, ‘Wait, how did you get an appointment?’ I wasn’t prepared for that kind of reaction. It took me off guard so I eventually stopped telling people I planned to get the vaccine.”
Vaccine supply issues resulted in the cancellation of two of her appointments, and the shaming even made her debate rescheduling. “I would never want to step in front of somebody who needed it,” said Ms. Coody. “Then I realized, I do need it. There are a lot of patients in hospitals waiting for care. I thought, it’s about them. It’s not about me and my shame or anybody else who doesn’t understand the situation.”
Getting policed about a hidden health issue isn’t new to Ms. Coody, who has a condition called dysautonomia, a disorder of the autonomic nervous system that can cause her to suddenly pass out. She said the vaccine shaming she has experienced was similar to when she’s been confronted after parking in a handicapped space, even though she has a tag that allows her to park there.
“People come up to me and say, ‘You’re young and you obviously don’t have an illness so why are you taking a handicap spot?’” Ms. Coody said. “Even though it’s none of their business, I feel the need to defend myself. If more people realized there are invisible illnesses out there, maybe they might be a little more respectful about it.”
Even total strangers waiting in vaccine lines have felt justified in interrogating someone who looks young and healthy. Those on the receiving end of the questions say the implication is that they must have cheated and jumped the line.
Joanna Hua, 23 and a graduate student at Georgetown University, was standing in line for her second dose recently when an older woman she’d never met confronted her. “She looked at me and said, ‘You look very young to be getting the vaccine,’” Ms. Hua recounted. “She asked me, ‘How did you end up being able to qualify for one?’”
Ms. Hua said she was taken aback by the question. She told the woman truthfully that she qualified because she worked in a grocery store, but she didn’t mention that she also qualified based on her weight. She said another young woman in line near her also nervously explained her reasons for qualifying.
“I felt an instinctive need to justify myself,” said Ms. Hua. “It felt almost accusatory and invasive to ask about it. I think there is some sort of idea going around that people are just taking advantage and trying to get a vaccine whenever possible. I don’t doubt that some people do that. But to have a stranger come up and ask you?”
Tanmoy Lala Das, a medical and doctoral student in New York City, has been helping with vaccination efforts in Manhattan, giving shots to patients and helping as a patient navigator. He said overall the experience at vaccination centers has been upbeat, and everyone is collegial and happy to be there. But he has, on occasion, heard people asking others about personal health issues while waiting in line for their shots.
“I’ve overheard people ask, ‘So what brings you in today?’” Mr. Das said. “The less stigmatized conditions people are open to talking about. They’d laugh and say, “Oh, you know, diabetes.’ I think the ones who are more sensitive, they say, ‘Oh, I just got a spot.’”
It doesn’t help that many people know someone who has jumped the line by claiming to be a teacher or a smoker or lying about a health condition. In New York a fitness instructor got vaccinated by claiming to be an educator, and in Florida two women even “dressed up as grannies” to get the vaccine.
“I think in New York, people are trying to figure out these dynamics of are you getting the dose because it was left over, or a condition that qualifies you or did you lie about something,” said Mr. Das. “The honest reality is I know people who have cut the line and lied about things — 29-year-old people who have gotten vaccines who don’t have pre-existing conditions. But I think most people are not lying. The goal is to vaccinate everyone.”
Rhonda Wolfson, who lives in Toronto, said that in places where the vaccination process still is age-restricted, it has created a different privacy problem, casting light on the fact that a person is above a certain age. Ms. Wolfson qualified for a pilot vaccination program in Ontario for people aged 60 to 64, and she realized that talking about her vaccination would reveal her as a sexagenarian to people who thought she was younger.
“I have one friend in her 40s, and she knows I’m older, but she doesn’t know my exact age,” said Ms. Wolfson. “She’s never asked, and I’ve never offered. I spoke to her last week and in my excitement I mentioned, ‘OMG, I got vaccinated.’ I could almost hear her pause, ‘Oh, you’re that age.’”
In some circles, the stigma of early vaccination is even more concerning because it could dissuade at-risk people from getting the shot. In the gay community, for instance, a young person who gets vaccinated in the early group might be seen to be immunocompromised.
“In the gay community there is this assumption that if you are getting the vaccine right now you must be secretly H.I.V. positive,” said Mr. Das, who is gay. “It has become an assumption in the community that if you’re a gay and you post a picture of the vaccine card, you’re positive and haven’t told us. I always talk to my friends and tell them, ‘Don’t assume things.’”
Mr. Das said he is hopeful that any stigma or medical privacy issues associated with early vaccination will disappear once vaccine appointments are open to everyone. President Biden has urged all states to expand medical eligibility to the general population by May 1, and many states, including Alaska, Arizona, Georgia and Mississippi, have already made the change.
“The sooner we get to vaccinating everyone, I think this question of ‘Oh, what qualified you?’ will stop,” Mr. Das said. “Once that goes away hopefully these barriers will break down, and people won’t keep asking these very personal questions.”
In “Hooked,” Michael Moss explores how no addictive drug can fire up the reward circuitry in our brains as rapidly as our favorite foods.
In a legal proceeding two decades ago, Michael Szymanczyk, the chief executive of the tobacco giant Philip Morris, was asked to define addiction. “My definition of addiction is a repetitive behavior that some people find difficult to quit,” he responded.
Mr. Szymanczyk was speaking in the context of smoking. But a fascinating new book by Michael Moss, an investigative journalist and best-selling author, argues that the tobacco executive’s definition of addiction could apply to our relationship with another group of products that Philip Morris sold and manufactured for decades: highly processed foods.
In his new book, “Hooked,” Mr. Moss explores the science behind addiction and builds a case that food companies have painstakingly engineered processed foods to hijack the reward circuitry in our brains, causing us to overeat and helping to fuel a global epidemic of obesity and chronic disease. Mr. Moss suggests that processed foods like cheeseburgers, potato chips and ice cream are not only addictive, but that they can be even more addictive than alcohol, tobacco and drugs. The book draws on internal industry documents and interviews with industry insiders to argue that some food companies in the past couple of decades became aware of the addictive nature of their products and took drastic steps to avoid accountability, such as shutting down important research into sugary foods and spearheading laws preventing people from suing food companies for damages.
In another cynical move, Mr. Moss writes, food companies beginning in the late 1970s started buying a slew of popular diet companies, allowing them to profit off our attempts to lose the weight we gained from eating their products. Heinz, the processed food giant, bought Weight Watchers in 1978 for $72 million. Unilever, which sells Klondike bars and Ben & Jerry’s ice cream, paid $2.3 billion for SlimFast in 2000. Nestle, which makes chocolate bars and Hot Pockets, purchased Jenny Craig in 2006 for $600 million. And in 2010 the private equity firm that owns Cinnabon and Carvel ice cream purchased Atkins Nutritionals, the company that sells low-carb bars, shakes and snacks. Most of these diet brands were later sold to other parent companies.
“The food industry blocked us in the courts from filing lawsuits claiming addiction; they started controlling the science in problematic ways, and they took control of the diet industry,” Mr. Moss said in an interview. “I’ve been crawling through the underbelly of the processed food industry for 10 years and I continue to be stunned by the depths of the deviousness of their strategy to not just tap into our basic instincts, but to exploit our attempts to gain control of our habits.”
A former reporter for The New York Times and recipient of the Pulitzer Prize, Mr. Moss first delved into the world of the processed food industry in 2013 with the publication of “Salt Sugar Fat.” The book explained how companies formulate junk foods to achieve a “bliss point” that makes them irresistible and market those products using tactics borrowed from the tobacco industry. Yet after writing the book, Mr. Moss was not convinced that processed foods could be addictive.
“I had tried to avoid the word addiction when I was writing ‘Salt Sugar Fat,’” he said. “I thought it was totally ludicrous. How anyone could compare Twinkies to crack cocaine was beyond me.”
But as he dug into the science that shows how processed foods affect the brain, he was swayed. One crucial element that influences the addictive nature of a substance and whether or not we consume it compulsively is how quickly it excites the brain. The faster it hits our reward circuitry, the stronger its impact. That is why smoking crack cocaine is more powerful than ingesting cocaine through the nose, and smoking cigarettes produces greater feelings of reward than wearing a nicotine patch: Smoking reduces the time it takes for drugs to hit the brain.
But no addictive drug can fire up the reward circuitry in our brains as rapidly as our favorite foods, Mr. Moss writes. “The smoke from cigarettes takes 10 seconds to stir the brain, but a touch of sugar on the tongue will do so in a little more than a half second, or six hundred milliseconds, to be precise,” he writes. “That’s nearly 20 times faster than cigarettes.”
This puts the term “fast food” in a new light. “Measured in milliseconds, and the power to addict, nothing is faster than processed food in rousing the brain,” he added.
Mr. Moss explains that even people in the tobacco industry took note of the powerful lure of processed foods. In the 1980s, Philip Morris acquired Kraft and General Foods, making it the largest manufacturer of processed foods in the country, with products like Kool-Aid, Cocoa Pebbles, Capri Sun and Oreo cookies. But the company’s former general counsel and vice president, Steven C. Parrish, confided that he found it troubling that it was easier for him to quit the company’s cigarettes than its chocolate cookies. “I’m dangerous around a bag of chips or Doritos or Oreos,” he told Mr. Moss. “I’d avoid even opening a bag of Oreos because instead of eating one or two, I would eat half the bag.”
As litigation against tobacco companies gained ground in the 1990s, one of the industry’s defenses was that cigarettes were no more addictive than Twinkies. It may have been on to something. Philip Morris routinely surveyed the public to gather legal and marketing intelligence, Mr. Moss writes, and one particular survey in 1988 asked people to name things that they thought were addictive and then rate them on a scale of 1 to 10, with 10 being the most addictive.
“Smoking was given an 8.5, nearly on par with heroin,” Mr. Moss writes. “But overeating, at 7.3, was not far behind, scoring higher than beer, tranquilizers and sleeping pills. This statistic was used to buttress the company’s argument that cigarettes might not be exactly innocent, but they were a vice on the order of potato chips and, as such, were manageable.”
But processed foods are not tobacco, and many people, including some experts, dismiss the notion that they are addictive. Mr. Moss suggests that this reluctance is in part a result of misconceptions about what addiction entails. For one, a substance does not have to hook everyone for it to be addictive. Studies show that most people who drink or use cocaine do not become dependent. Nor does everyone who smokes or uses painkillers become addicted. It is also the case that the symptoms of addiction can vary from one person to the next and from one drug to another. Painful withdrawals were once considered hallmarks of addiction. But some drugs that we know to be addictive, such as cocaine, would fail to meet that definition because they do not provoke “the body-wrenching havoc” that withdrawal from barbiturates and other addictive drugs can cause.
The American Psychiatric Association now lists 11 criteria that are used to diagnose what it calls a substance use disorder, which can range from mild to severe, depending on how many symptoms a person exhibits. Among those symptoms are cravings, an inability to cut back despite wanting to, and continuing to use the substance despite it causing harm. Mr. Moss said that people who struggle with processed food can try simple strategies to conquer routine cravings, like going for a walk, calling a friend or snacking on healthy alternatives like a handful of nuts. But for some people, more extreme measures may be necessary.
“It depends where you are on the spectrum,” he said. “I know people who can’t touch a grain of sugar without losing control. They would drive to the supermarket and by the time they got home their car would be littered with empty wrappers. For them, complete abstention is the solution.”
The pandemic has shed a blinding light on too many Americans’ failure to follow the well-established scientific principles of personal health and well-being. There are several reasons this country, one of the world’s richest and most highly developed, has suffered much higher rates of Covid-19 infections and deaths than many poorer and less well-equipped populations.
Older Americans have been particularly hard hit by this novel coronavirus. When cases surged at the end of last year, Covid-19 became the nation’s leading cause of death, deadlier than heart disease and cancer.
But while there’s nothing anyone can do to stop the march of time, several leading risk factors for Covid-19 infections and deaths stem from how many Americans conduct their lives from childhood on and their misguided reliance on medicine to patch up their self-inflicted wounds.
After old age, obesity is the second leading risk factor for death among those who become infected and critically ill with Covid-19. Seventy percent of Americans adults are now overweight, and more than a third are obese. Two other major risks for Covid, Type 2 diabetes and high blood pressure, are most often the result of excess weight, which in turn reflects unhealthy dietary and exercise habits. These conditions may be particularly prevalent in communities of color, who are likewise disproportionately affected by the pandemic.
Several people I know packed on quite a few pounds of health-robbing body fat this past year, and not because they lacked the ability to purchase and consume a more nutritious plant-based diet or to exercise regularly within or outside their homes. One male friend in his 50s unexpectedly qualified for the Covid vaccine by having an underlying health condition when his doctor found he’d become obese since the pandemic began.
A Harris Poll, conducted for the American Psychological Association in late February, revealed that 42 percent of respondents had gained an average of 29 “pandemic pounds,” increasing their Covid risk.
So what can we learn from these trends? Tom Vilsack, the new Secretary of Agriculture, put it bluntly a week ago in Politico Pro’s Morning Agriculture newsletter: “We cannot have the level of obesity. We cannot have the level of diabetes we have. We cannot have the level of chronic disease … It will literally cripple our country.”
Of course, in recent decades many of the policies of the department Mr. Vilsack now heads have contributed mightily to Americans’ access to inexpensive foods that flesh out their bones with unwholesome calories and undermine their health. Two telling examples: The government subsidizes the production of both soybeans and corn, most of which is used to feed livestock.
Not only does livestock production make a major contribution to global warming, much of its output ends up as inexpensive, often highly processed fast foods that can prompt people to overeat and raise their risk of developing heart disease, diabetes, high blood pressure and kidney disease. But there are no subsidies for the kinds of fruits and vegetables that can counter the disorders that render people more vulnerable to the coronavirus.
As Mr. Vilsack said, “The time has come for us to transform the food system in this country in an accelerated way.”
Early in the pandemic, when most businesses and entertainment venues were forced to close, toilet paper was not the only commodity stripped from market shelves. The country was suddenly faced with a shortage of flour and yeast as millions of Americans “stuck” at home went on a baking frenzy. While I understood their need to relieve stress, feel productive and perhaps help others less able or so inclined, bread, muffins and cookies were not the most wholesome products that might have emerged from pandemic kitchens.
When calorie-rich foods and snacks are in the home, they can be hard to resist when there’s little else to prompt the release of pleasure-enhancing brain chemicals. To no one’s great surprise, smoking rates also rose during the pandemic, introducing yet another risk to Covid susceptibility.
And there’s been a run on alcoholic beverages. National sales of alcohol during one week in March 2020 were 54 percent higher than the comparable week the year before. The Harris Poll corroborated that nearly one adult in four drank more alcohol than usual to cope with pandemic-related stress. Not only is alcohol a source of nutritionally empty calories, its wanton consumption can result in reckless behavior that further raises susceptibility to Covid.
Well before the pandemic prompted a rise in calorie consumption, Americans were eating significantly more calories each day than they realized, thanks in large part to the ready availability of ultra-processed foods, especially those that tease, “you can’t eat just one.” (Example: Corn on the cob is unprocessed, canned corn is minimally processed, but Doritos are ultra-processed).
In a brief but carefully designed diet study, Kevin D. Hall and colleagues at the National Institutes of Health surreptitiously gave 20 adults diets that were rich in either ultra-processed foods or unprocessed foods matched for calorie, sugar, fat, sodium, fiber and protein content. Told to eat as much as they wanted, the unsuspecting participants consumed 500 calories a day more on the ultra-processed diet.
If you’ve been reading my column for years, you already know that I’m not a fanatic when it comes to food. I have many containers of ice cream in my freezer; cookies, crackers and even chips in my cupboard; and I enjoy a burger now and then. But my daily diet is based primarily on vegetables, with fish, beans and nonfat milk my main sources of protein. My consumption of snacks and ice cream is portion-controlled and, along with daily exercise, has enabled me to remain weight-stable despite yearlong pandemic stress and occasional despair.
As Marion Nestle, professor emerita of nutrition, food studies and public health at New York University, says, “This is not rocket science.” She does not preach deprivation, only moderation (except perhaps for a total ban on soda). “We need a national policy aimed at preventing obesity,” she told me, “a national campaign to help all Americans get healthier.”
Over the past year, many scientific teams around the world have reported that obese people who contract the coronavirus are especially likely to become dangerously ill.
Now, a large new study, of nearly 150,000 adults at more than 200 hospitals across the United States, paints a more detailed picture of the connection between weight and Covid-19 outcomes.
The study, performed by a team of researchers as the Centers for Disease Control and Prevention, has confirmed that obesity significantly increases the risk for hospitalization and death among those who contract the virus. And among those who are obese, the risk increases as a patient’s body mass index, or B.M.I., a ratio of weight to height, increases. Patients with a B.M.I. of 45 or higher, which corresponds to severe obesity, were 33 percent more likely to be hospitalized and 61 percent more likely to die than those who were at a healthy weight, the researchers found.
“The findings of the study highlight the serious clinical public health implications of elevated B.M.I., and they suggest the continued need for intensive management of Covid-19 illness, especially among patients affected by severe obesity,” said the lead author, Lyudmyla Kompaniyets, a health economist at the Division of Nutrition, Physical Activity and Obesity at the C.D.C.
But the relationship between weight and outcomes is nuanced. Covid-19 patients who were underweight were also more likely to be hospitalized than those who were at a healthy weight, although they were not more likely to be admitted to the intensive care unit or to die.
Dr. Kompaniyets and her colleagues used a database of Covid-19 cases to identify 148,494 adults who received a diagnosis of the disease at American hospitals from last March to December. They calculated the B.M.I. of each patient and looked for correlations between B.M.I. and a variety of serious outcomes, including hospitalization, I.C.U. admission, mechanical ventilation and death.
They found that obesity, which is defined as a B.M.I. of 30 or higher, increased the risk of both hospitalization and death. Patients with a B.M.I. of 30 to 34.9 were just 7 percent more likely to be hospitalized and 8 percent more likely to die than people who were at a healthy weight, but the risks increased sharply as B.M.I. rose.
Providing evidence for this kind of “dose response” relationship makes the study particularly compelling, said Dr. Anne Dixon, the director of pulmonary and critical care medicine at the University of Vermont Medical Center, who was not involved in the research. “What it shows is the more severe your obesity, the worse the effect is. And the fact that goes up stepwise with increasing levels of obesity, I think, adds sort of biological plausibility to the relationship between obesity and the outcome.”
The connection between obesity and poor outcomes was strongest among patients under 65, but it held even for older adults. Previous, smaller studies have not found strong links between obesity and severity of Covid-19 in older adults.
“Potentially because they had more power from this large sample size, they’ve demonstrated that obesity remains an important risk factor for death in older adults as well,” said Dr. Michaela R. Anderson, an expert in pulmonary and critical care medicine at Columbia University Medical Center, who was not involved in the study. “It’s a beautifully done study with a massive population.”
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Dr. Kompaniyets and her colleagues also documented a linear relationship between B.M.I. and the likelihood of needing mechanical ventilation; the higher the B.M.I., the more likely a patient was to require such intervention, which is invasive and can come with serious complications.
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The study also found that patients who were underweight, with a B.M.I. below 18.5, were 20 percent more likely to be hospitalized than those who had a healthy weight. The reasons are not entirely clear, but may stem from the fact that some of these patients were malnourished or frail or had other diseases.
The B.M.I. range associated with the best outcomes, the researchers found, was near the dividing line between what is considered healthy and overweight, consistent with some prior research suggesting that a few extra pounds might help protect people when they contract an infectious disease.
“Exactly why that association exists is currently unknown,” said Dr. Alyson Goodman, a pediatrician and medical epidemiologist at the C.D.C. and a co-author of the study. One possibility is that having a bit of extra fat may provide much needed energy reserves over the course of a long illness.
The findings highlight the importance of carefully managing the care of patients who are severely obese and of ensuring that people who are obese have access to vaccines and other preventive measures.
“This just provides further evidence for the recommendation to vaccinate those with a high B.M.I. as early as feasible,” said Sara Y. Tartof, an infectious disease epidemiologist at the Department of Research & Evaluation at Kaiser Permanente, who was not involved in the study.
Rebecca O’Neal didn’t believe she qualified for a Covid-19 vaccine. She had not realized that her turn had come. Last week, when she scrolled through the eligibility requirements for the state of New York, she noticed body mass index on the list.
Body mass index, or B.M.I., is technically a measure of obesity. The quantifier was drawn up in the 1930s by the Metropolitan Life Insurance Company to assess risk. Since a B.M.I. is a formula that does not consider several important factors like where the body fat is or if any vital organs are surrounded by fat, experts say to take the indicator with a grain of salt. But even so, a B.M.I. that indicates obesity has been a source of agitation for people who believe their doctors have used it to discriminate against them because of their weight.
Ms. O’Neal, a 34-year-old comedian and writer in Brooklyn, didn’t worry about that in the moment. She calculated her B.M.I. (it’s essentially your weight compared to your height), found that she met this technical threshold for obesity, and booked a vaccine appointment for the same day. She received the first dose later that afternoon.
“I didn’t know that my B.M.I. was 30,” Ms. O’Neal said in a phone interview. “I cracked a lot of jokes about it on Twitter, but it was a relief that I was eligible at all.”
Ms. O’Neal is one of millions of Americans, in states like New York, Utah and Texas, who are qualified to be vaccinated based on their B.M.I. While obesity has been linked to more severe cases of Covid-19, of the 500,000 Americans who have died from the coronavirus, 17,770 were overweight and had obesity listed as a contributing factor in their death, according to the Centers for Disease Control and Prevention.
Relying on a B.M.I. to judge one’s risk of serious health conditions is complicated. Many healthy people still fall in the “overweight” category based on their body proportions, with no distinction made between bone density, muscle mass and body fat.
This is particularly the case for women, Black adults and people with low incomes who make up the majority of Americans who have been diagnosed with obesity by such standards. That has a lot to do with the fact that the original calculus was developed by and for white men.
For many, using their misleading high B.M.I. to get inoculated is a fraught decision.
As Emma Specter put it in Vogue, writing about her decision to get a vaccine based on the B.M.I. qualification: “A metric of health that has long been called into question by fat activists and medical experts alike could stand to actively benefit fat people for the first time.”
Many other people are making the same decision — and posting about it online.
Some wrestled with whether it was ethical to receive a vaccine based on a metric that could have little bearing on their risk of serious illness.
“Taking care of the sick and the elderly and the health care workers, I understand all that — but at some point they should have open it to whoever can grab,” Raffaele Rispo, 38, a barber from Saratoga Springs, N.Y. who received a vaccine recently because of his B.M.I., said in an interview. “I understood that the older, more sick should get it first — but when they changed it, I was happy.”
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Mr. Rispo has not seen his parents, who live two-and-a-half hours away from him, or his 15-year-old son who also lives a few hours away, in a year. He was ready to return to “some normalcy,” even though he understood B.M.I.’s are unreliable, he said.
While unreliable, a B.M.I. can serve a purpose; it can be used to screen for weight categories that may lead to health problems, according to the C.D.C., but it is not diagnostic of the person’s body fat or health.
“B.M.I. by itself is not a great measure,” said Dr. Fatima Cody Stanford, an expert in obesity medicine and nutrition at Harvard Medical School. “It doesn’t tell me if that’s fat mass that’s causing inflammation. It doesn’t tell me if that’s water weight, it doesn’t give me those types of specific details.”
For those who do meet the B.M.I. requirement for the vaccine, that measurement has presented a rare opportunity. William Antonelli said that once his sister realized that she qualified for the vaccine because of her B.M.I., she set up an appointment for him, too. A few days later, Mr. Antonelli, 24, an editor at Insider, received his first vaccine jab.
“When it comes to a disease like this, there really is not a wrong person to vaccinate,” he said. “The problem is not me applying for something I am eligible for, it’s the rollout. The issue lies with the government system that has led us to this point.”
When the pandemic struck last year, many Americans rushed to stock up on alcohol, causing retail sales of wine, beer and liquor to surge across the country.
But the uptick in sales was a worrying sign for health experts focused on cancer prevention. In recent years, a growing number of medical and public health groups have introduced public awareness campaigns warning people to drink with caution, noting that alcohol is the third leading preventable cause of cancer, behind tobacco and obesity.
In October, the American Society for Clinical Oncology (ASCO), which represents many of the nation’s top cancer doctors, along with the American Institute for Cancer Research, the American Public Health Association and five other groups called on the federal government to add a cancer warning to alcohol labels, saying there was strong scientific consensus that alcohol can cause several types of cancer, including breast and colon cancers. While medical experts have long recognized alcohol as a risk factor for various cancers, including cancers of the mouth, throat, voice box, esophagus and liver, a survey conducted by ASCO in 2017 of 4,016 American adults found that fewer than a third recognized alcohol as a risk factor for cancer.
Other countries are stepping up public health efforts to rein in alcohol consumption as well. The European Union, which has some of the highest levels of drinking in the world, announced earlier this year that it planned to slap new health warnings on alcohol and explore new taxes and restrictions on the marketing of alcoholic beverages as part of a $4.8 billion plan to reduce cancer rates. In France, famous for its wine and champagne, the government announced that it would issue new warnings and policies to discourage heavy drinking as part of a 10-year plan to tackle cancer, which is the country’s leading cause of death.
The ongoing pandemic underscores the urgency of these efforts, as stress, lockdowns and economic uncertainty continue to take a toll. In the past year, hospitals across the United States have reported an increase in admissions for hepatitis, liver failure and other alcohol-related diseases. A study in the journal Psychiatry Research found that in the first six months of lockdowns, alcohol abuse rose most sharply among people who lost their jobs or who were confined to their homes because of shelter-in-place restrictions. The pandemic has also made it easier for people working from home to drink throughout the day without fear of colleagues noticing.
“Workers who would never consider consuming alcohol at the office are now free to drink to excess during work hours while at home,” the study found. “There are grave concerns over the long-term health implications of the rising level of alcohol dependence.”
In the United States, 41 percent of men and 39 percent of women will develop cancer at some point in their lifetimes, according to the American Cancer Society. The group estimates that around 42 percent of newly diagnosed cancers are potentially preventable, by avoiding such measures as cigarette smoking (accounting for some 19 percent of cancer cases), excess weight (7.8 percent of cases), drinking alcohol (5.6 percent of cases), ultraviolet radiation (5 percent of cases) and physical inactivity (2.9 percent of cases). While heavy drinking poses the greatest hazard, moderate drinking — generally defined as two drinks a day for men and one drink a day for women — can also imperil health. According to the cancer society, even small amounts of alcohol — less than one drink a day — can raise the risk of breast cancer in women and some other forms of the disease.
The link between alcohol and cancer was the focus of a recent large study that found that alcohol causes 75,000 new cases of cancer in America every year, as well as 19,000 deaths from the disease. The study, published in January in Cancer Epidemiology, concluded that alcohol accounted for more than one in eight cases of breast cancer in women and one in 10 cases of colorectal and liver cancers nationwide.
“It’s a substantial number of cancer cases and cancer deaths that could be prevented,” said Dr. Farhad Islami, the senior author of the study and the scientific director of the cancer disparity research team at the American Cancer Society. “The cancer burden is considerable.”
Scientists have known that alcohol promotes cancer for several decades. The World Health Organization first classified alcohol consumption as cancer-causing in 1987. Experts say that all types of alcoholic beverages can increase cancer risk because they all contain ethanol, which can cause DNA damage, oxidative stress and cell proliferation. Ethanol is metabolized by the body into another carcinogen, acetaldehyde, and it can influence breast cancer risk by elevating estrogen levels.
But surveys continue to show that most people remain unaware of the risks. When the American Institute for Cancer Research surveyed Americans two years ago to gauge their awareness of different cancer risk factors, the results were striking: fewer than half were aware of the alcohol-cancer link.
Experts say one reason for the lack of awareness is the popular idea that moderate alcohol intake, especially of red wine, is good for heart health, which has drowned out public health messages about alcohol’s impact on cancer risk. But while moderate drinking has long had a health halo, recent studies suggest it may not be beneficial at all. The American Heart Association states that “no research has established a cause-and-effect link between drinking alcohol and better heart health,” and that people who drink red wine may have lower rates of heart disease for other reasons, such as healthier lifestyles, better diets or higher socioeconomic status.
Other analyses have found that moderate drinking can appear to be beneficial in large population studies because the “nondrinkers” who are used for comparison often include people who don’t drink because they have serious health issues or because they are former heavy drinkers. When studies take these factors into account, the apparent cardiovascular benefits of moderate drinking disappear.
For that reason, the federal government’s Dietary Guidelines for Americans, which once promoted moderate drinking for heart health, no longer makes that claim. A panel of scientists that helped shape the most recent edition of the guidelines called for the government to lower the recommended daily limit for alcohol consumption to just one drink a day for both men and women, citing evidence that higher levels of alcohol intake increase the risk of early death.
But the alcohol industry lobbied fiercely against that change, and the latest guidelines, published in December, did not include the lowered drink recommendation. The guidelines, however, did for the first time include strong language about alcohol and cancer, warning that even moderate drinking can “increase the overall risk of death from various causes, such as from several types of cancer and some forms of cardiovascular disease.”
“For some types of cancer,” the new guidelines state, “the risk increases even at low levels of alcohol consumption (less than one drink in a day). Caution, therefore, is recommended.”
The American Cancer Society also issued new guidelines last year that for the first time took a tough stance on drinking, warning that for cancer prevention, “there is no safe level of consumption.” Dr. Timothy Naimi, a member of the government’s dietary guidelines advisory committee, said the new recommendations make clear that moderate drinking is not protective and that drinking less is always better than drinking more.
“The new guidelines are very strong in framing alcohol as a leading preventable health hazard,” said Dr. Naimi, the director of the Canadian Institute for Substance Use Research. “I think the relationship between alcohol and a number of the most important cancers is still not widely recognized. But I feel that’s changing.”
Nigel Brockton, the vice president of research at the American Institute for Cancer Research, said he worried that people who increased their alcohol intake in the past year to cope with the pandemic might continue their new habits into the future. But he advised people who drink to avoid making it a daily habit, and to take other steps to lower their risk, such as exercising and improving their diets.
“We’re not expecting everyone to become teetotalers,” he said. “But if you’re going to drink, then one is better than two, and not every day, because those are the behaviors that across all of these cancers increase your risk.”
Hace cinco años, un grupo de científicos especializados en nutrición estudiaron lo que comían los estadounidenses y llegaron a conclusiones sorprendentes: más de la mitad de todas las calorías que consume el estadounidense promedio procede de alimentos ultraprocesados, los cuales definen como “fórmulas industriales” que combinan grandes cantidades de azúcar, sal, aceites, grasas y otros aditivos.
Pese a que se les asocia con la obesidad, las cardiopatías, la diabetes tipo 2 y otros problemas de salud, los alimentos altamente procesados siguen siendo predominantes en la dieta de los estadounidenses. Son baratos, prácticos y están diseñados para que sepan bien. La industria de los alimentos los comercializa de manera entusiasta. Pero una cantidad cada vez mayor de científicos afirma que otra razón por la que estos alimentos se consumen tanto es porque para muchas personas no solo son apetecibles, sino adictivos, una idea que ha provocado controversia entre los investigadores.
Recientemente, la revista American Journal of Clinical Nutrition analizó la ciencia detrás de la adicción alimentaria y si los alimentos ultraprocesados podrían estar contribuyendo a comer en exceso y a la obesidad. Destacó un debate entre dos de los principales expertos en el tema, Ashley Geardhardt, profesora adjunta en el Departamento de Psicología de la Universidad de Míchigan, y Johannes Hebebrand, director del Departamento de Psiquiatría, Psicosomática y Psicoterapia para Niños y Adolescentes de la Universidad de Duisburgo-Essen, en Alemania.
Gearhardt, psicóloga clínica, ayudó a desarrollar la Escala de Adicción a los Alimentos de la Universidad de Yale, que es un estudio que se emplea para determinar si una persona muestra indicios de comportamiento adictivo hacia la comida. En un estudio en el que participaron más de 500 personas, ella y sus colegas descubrieron que ciertos alimentos tenían una especial propensión a provocar comportamientos relacionados con la alimentación “parecidos a los de las adicciones”, como compulsión intensa, pérdida del control e incapacidad de reducir su consumo a pesar de experimentar consecuencias perjudiciales y muchas ganas de dejar de comerlos.
Al principio de la lista estaba la pizza, el chocolate, las galletas, el helado, todo tipo de papas fritas y las hamburguesas con queso. Geardhardt ha descubierto en su investigación que estos alimentos tan procesados tienen mucho en común con las sustancias adictivas. Al igual que los cigarrillos y la cocaína, sus ingredientes se derivan de plantas presentes en la naturaleza y de alimentos a los que se les retiran los componentes que ralentizan su absorción, como la fibra, el agua y la proteína. Posteriormente, sus ingredientes más atractivos se refinan y procesan para crear productos que se absorben con rapidez dentro del torrente sanguíneo, lo cual aumenta su capacidad para activar las regiones del cerebro que regulan la sensación de gratificación, las emociones y la motivación.
Gearhardt señaló que la sal, los espesantes, los sabores artificiales y otros aditivos de los alimentos muy procesados refuerzan su seducción al mejorar algunas propiedades como la textura y la sensación que produce en la boca, lo cual se asemeja a la manera en que los cigarrillos contienen una serie de aditivos diseñados para aumentar su potencial adictivo. Por ejemplo, el mentol ayuda a enmascarar el sabor amargo de la nicotina, mientras que otro ingrediente usado en algunos cigarrillos, el cacao, dilata las vías aéreas y aumenta la absorción de la nicotina.
Según Geardhardt, un común denominador de los alimentos ultraprocesados más irresistibles es que contienen grandes cantidades de grasa y carbohidratos refinados, una combinación poderosa que pocas veces se encuentra en los alimentos de origen natural que el ser humano ha evolucionado para consumir, como frutas, vegetales, carne, nueces, miel, frijoles y semillas. Muchos alimentos que encontramos en la naturaleza son ricos en grasas o carbohidratos, pero por lo general no son altos en las dos cosas.
“Las personas no presentan una respuesta conductual adictiva a los alimentos naturales que son buenos para la salud, como las fresas”, afirmó Gearhardt, quien también es directora del Laboratorio de Ciencia de la Alimentación y la Adicción y su Tratamiento en Míchigan. “El subconjunto de alimentos muy procesados está diseñado de un modo muy parecido a cómo producimos otras sustancias adictivas. Estos son los alimentos que pueden ocasionar la pérdida de control y los comportamientos compulsivos y problemáticos que se asemejan a lo que observamos con el alcohol y los cigarrillos”.
En un estudio, Gearhardt descubrió que cuando las personas reducían el consumo de alimentos muy procesados, experimentaban síntomas parecidos a la abstinencia que se observa en los drogadictos, como irritabilidad, fatiga, tristeza y compulsión. En estudios de imágenes del cerebro, otros investigadores han descubierto que las personas que a menudo consumen comida chatarra, con el tiempo pueden desarrollar tolerancia a ella, lo que hace que cada vez requieran mayores cantidades para obtener la misma satisfacción.
En su práctica clínica, Gearhardt ha visto pacientes —algunos obesos y otros no— que luchan en vano para controlar su ingesta de alimentos muy procesados. Algunos intentan comerlos con moderación, pero solo terminan perdiendo el control y comen hasta el punto de vomitar y sentirse angustiados. Muchos de sus pacientes ven que no pueden dejar estos alimentos pese a que tienen dificultades para controlar su diabetes y presentan un aumento excesivo de peso y otros problemas de salud.
“Lo sorprendente es que mis clientes son casi siempre muy conscientes de las consecuencias negativas de su consumo de alimentos altamente procesados, y normalmente han probado docenas de estrategias como dietas de choque y limpiezas para intentar controlar su relación con estos alimentos”, dijo. “Aunque estos intentos pueden funcionar durante un corto periodo de tiempo, casi siempre acaban recayendo”.
Sin embargo, Hebebrand rebate la idea de que algún alimento provoque adicción. Aunque las papas fritas y la pizza pueden parecer irresistibles para algunas personas, él sostiene que no ocasionan un estado mental alterado, lo que es característico de las sustancias adictivas. Por ejemplo, señaló, fumar un cigarrillo, beber una copa de vino o recibir una dosis de heroína provocan una sensación inmediata en el cerebro que los alimentos no producen.
“Siempre sucede que con cualquier droga adictiva casi toda la gente experimenta un estado mental alterado después de consumirla”, señaló Hebebrand. “Eso indica que la sustancia está causando un efecto en nuestro sistema nervioso central. Pero todos ingerimos alimentos muy procesados y nadie siente este estado mental alterado porque la sustancia no llega directamente al cerebro”.
En los trastornos por consumo de sustancias, las personas se vuelven dependientes de una sustancia química específica que actúa en el cerebro, como la nicotina de los cigarrillos o el etanol del vino y el licor. Al principio buscan esta sustancia química para obtener un subidón, y luego se vuelven dependientes de ella para aliviar las emociones negativas y depresivas. Pero en los alimentos altamente procesados no hay ningún compuesto que pueda señalarse como adictivo, dijo Hebebrand. De hecho, la evidencia sugiere que las personas obesas que comen en exceso tienden a consumir una amplia gama de alimentos con diferentes texturas, sabores y composiciones. Hebebrand argumentó que comer en exceso se debe, en parte, a que la industria de alimentos comercializa más de 20.000 productos nuevos cada año, lo que da a la gente acceso a una variedad aparentemente interminable de comidas y bebidas.
“Es la diversidad de alimentos la que resulta tan atractiva y causa el problema, no una sola sustancia en estas comidas”, añadió.
Quienes argumentan en contra de la idea de la adicción a los alimentos también señalan que la mayoría de las personas consumen diariamente alimentos altamente procesados sin mostrar ningún signo de adicción. Pero Gearhardt señala que las sustancias adictivas no enganchan a todos los que las consumen. Según las investigaciones, alrededor de dos tercios de las personas que fuman cigarrillos acaban convirtiéndose en adictos, mientras que un tercio no lo hace. Solo un 21 por ciento de las personas que consumen cocaína a lo largo de su vida se convierten en adictos, mientras que solo un 23 por ciento de las personas que beben alcohol desarrollan una dependencia de este. Los estudios sugieren que hay una amplia gama de factores que determinan que las personas se vuelvan adictas, como su genética, sus antecedentes familiares, su exposición a traumas y sus antecedentes ambientales y socioeconómicos.
“La mayoría de la gente prueba sustancias adictivas y no se vuelve adicta”, dijo Gearhardt. “Así que si estos alimentos son adictivos, no esperaríamos que toda la sociedad se convirtiese en adicta a ellos”.
A las personas que tienen problemas para restringir su ingesta de alimentos muy procesados, Gearhardt les recomienda llevar un registro de todo lo que comen para poder identificar los alimentos que ejercen una mayor atracción, es decir, los que producen una fuerte compulsión y que no se pueden dejar de comer una vez que se inicia el consumo. No se debe tener esos alimentos en casa y, en cambio, es recomendable llenar el refrigerador y la despensa con otras alternativas que les gusten y sean más saludables, señaló.
Se recomienda llevar un registro de los factores desencadenantes que provocan antojos y atracones. Pueden ser emociones como el estrés, el aburrimiento o la soledad. O puede ser el Dunkin’ Donuts por el que pasas en carro tres veces a la semana. Elabora un plan para controlar esos factores desencadenantes como, por ejemplo, tomar una ruta diferente para volver a casa o realizar actividades no alimentarias para aliviar el estrés y el aburrimiento. Y evita saltarte las comidas, porque el hambre puede desencadenar antojos que conduzcan a decisiones lamentables, dijo.
“Con el fin de poder transitar mejor un entorno alimentario muy desafiante, es importante asegurarte de proporcionarle a tu cuerpo alimentos nutritivos y muy poco procesados que te gusten con regularidad”, comentó Gearhardt.
Anahad O’Connor cubre temas de salud, ciencia, nutrición y otros. También es el autor de libros de salud exitosos como Never Shower in a Thunderstorm y The 10 Things You Need to Eat.
A young girl carries harvested food, part of the traditional hunting and gathering lifestyle of the Shuar of Amazonian Ecuador.Credit…Samuel S. Urlacher, Ph.D.
When children gain excess weight, the culprit is more likely to be eating too much than moving too little, according to a fascinating new study of children in Ecuador. The study compared the lifestyles, diets and body compositions of Amazonian children who live in rural, foraging communities with those of other Indigenous children living in nearby towns, and the results have implications for the rising rates of obesity in both children and adults worldwide.
The in-depth study found that the rural children, who run, play and forage for hours, are leaner and more active than their urban counterparts. But they do not burn more calories day-to-day, a surprising finding that implicates the urban children’s modernized diets in their weight gain. The findings also raise provocative questions about the interplay of physical activity and metabolism and why exercise helps so little with weight loss, not only in children but the rest of us, too.
The issue of childhood obesity is of pressing global interest, since the incidence keeps rising, including in communities where it once was uncommon. Researchers variously point to increasing childhood inactivity and junk food diets as drivers of youthful weight gain. But which of those concerns might be more important — inactivity or overeating — remains murky and matters, as obesity researchers point out, because we cannot effectively respond to a health crisis unless we know its causes.
That question drew the interest of Sam Urlacher, an assistant professor of anthropology at Baylor University in Waco, Texas, who for some time has been working among and studying the Shuar people. An Indigenous population in Amazonian Ecuador, the traditional Shuar live primarily by foraging, hunting, fishing and subsistence farming. Their days are hardscrabble and physically demanding, their diets heavy on bananas, plantains and similar starches, and their bodies slight. The Shuar, especially the children, are rarely overweight. They also are not often malnourished.
But were their wiry frames a result mostly of their active lives, Dr. Urlacher wondered? As a postgraduate student, he had worked with Herman Pontzer, an associate professor of evolutionary anthropology at Duke University, whose research focuses on how evolution may have shaped our metabolisms and vice versa.
In Dr. Pontzer’s pioneering research with the Hadza, a tribe of hunter-gatherers in Tanzania, he found that, although the tribespeople moved frequently during the day, hunting, digging, dragging, carrying and cooking, they burned about the same number of total calories daily as much-more-sedentary Westerners.
Dr. Pontzer concluded that, during evolution, we humans must have developed an innate, unconscious ability to reallocate our body’s energy usage. If we burn lots of calories with, for instance, physical activity, we burn fewer with some other biological system, such as reproduction or immune responses. The result is that our average, daily energy expenditure remains within a narrow band of total calories, helpful for avoiding starvation among active hunter-gatherers, but disheartening for those of us in the modern world who find that more exercise does not equate to much, if any, weight loss. (Dr. Pontzer’s highly readable new book on this topic, “Burn,” will be published on March 2. )
Dr. Pontzer’s work focuses primarily on Hadza adults, but Dr. Urlacher wondered if similar metabolic trade-offs might also exist in children, including among the traditional Shuar. So, for a 2019 study, he precisely measured energy expenditure in some of the young Shuar and compared the total number of calories they incinerated with existing data about the daily calories burned by relatively sedentary (and much heavier) children in the United States and Britain. And the totals matched. Although the young Shuar were far more active, they did not burn more calories, over all.
Young Shuar differ from most Western children in so many ways, though, including their genetics, that interpreting that study’s findings was challenging, Dr. Urlacher knew. But he also was aware of a more-comparable group of children only a longish canoe ride away, among Shuar families that had moved to a nearby market town. Their children regularly attended school and ate purchased foods but remained Shuar.
So, for the newest study, which was published in January in The Journal of Nutrition, he and his colleagues gained permission from Shuar families, both rural and relatively urban, to precisely measure the body compositions and energy expenditure of 77 of their children between the ages of 4 and 12, while also tracking their activities with accelerometers and gathering data about what they ate.
The urban Shuar children proved to be considerably heavier than their rural counterparts. About a third were overweight by World Health Organization criteria. None of the rural children were. The urban kids also generally were more sedentary. But all of the children, rural or urban, active or not, burned about the same number of calories every day.
What differed most were their diets. The children in the market town ate far more meat and dairy products than the rural children, along with new starches, like white rice, and highly processed foods, like candy. In general, they ate more and in a more-modern way than the rural children, and it was this diet, Dr. Urlacher and his colleagues conclude, that contributed most to their higher weight.
These findings should not romanticize the forager or hunter-gatherer lifestyle, Dr. Urlacher cautions. Rural, traditional Shuar children face frequent parasitic and other infections, as well as stunted growth, in large part because their bodies seem to shunt available calories to other vital functions and away from growing, Dr. Urlacher believes.
But the results do indicate that how much children eat influences their body weight more than how much they move, he says, an insight that should start to guide any efforts to confront childhood obesity.
“Exercise is still very important for children, for all sorts of reasons,” Dr. Urlacher says. “But keeping physical activity up may not be enough to deal with childhood obesity.”
A few years ago, routine lab tests showed that Susan Glickman Weinberg, then a 65-year-old clinical social worker in Los Angeles, had a hemoglobin A1C reading of 5.8 percent, barely above normal.
“This is considered prediabetes,” her internist told her. A1C measures how much sugar has been circulating in the bloodstream over time. If her results reached 6 percent — still below the number that defines diabetes, which is 6.5 — her doctor said he would recommend the widely prescribed drug metformin.
“The thought that maybe I’d get diabetes was very upsetting,” recalled Ms. Weinberg, who as a child had heard relatives talking about it as “this mysterious terrible thing.”
She was already taking two blood pressure medications, a statin for cholesterol and an osteoporosis drug. Did she really need another prescription? She worried, too, about reports at the time of tainted imported drugs. She wasn’t even sure what prediabetes meant, or how quickly it might become diabetes.
“I felt like Patient Zero,” she said. “There were a lot of unknowns.”
Now, there are fewer unknowns. A longitudinal study of older adults, published online this month in the journal JAMA Internal Medicine, provides some answers about the very common in-between condition known as prediabetes.
The researchers found that over several years, older people who were supposedly prediabetic were far more likely to have their blood sugar levels return to normal than to progress to diabetes. And they were no more likely to die during the follow-up period than their peers with normal blood sugar.
“In most older adults, prediabetes probably shouldn’t be a priority,” said Elizabeth Selvin, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health in Baltimore and the senior author on the study.
Prediabetes, a condition rarely discussed as recently as 15 years ago, refers to a blood sugar level that is higher than normal but that has not crossed the threshold into diabetes. It is commonly defined by a hemoglobin A1C reading of 5.7 to 6.4 percent or a fasting glucose level of 100 to 125 mg/dL; in midlife, it can portend serious health problems.
A diagnosis of prediabetes means that you are more likely to develop diabetes, and “that leads to downstream illness,” said Dr. Kenneth Lam, a geriatrician at the University of California, San Francisco, and an author of an editorial accompanying the study. “It damages your kidneys, your eyes and your nerves. It causes heart attack and stroke,” he said.
But for an older adult just edging into higher blood sugar levels, it’s a different story. Those fearful consequences take years to develop, and many people in their 70s and 80s will not live long enough to encounter them.
That fact has generated years of debate. Should older people with slightly above-normal blood sugar readings — a frequent occurrence since the pancreas produces less insulin in later life — be taking action, as the American Diabetes Association has urged?
Or does labeling people prediabetic merely “medicalize” a normal part of aging, creating needless anxiety for those already coping with multiple health problems?
Dr. Selvin and her colleagues analyzed the findings of an ongoing national study of cardiovascular risk that began in the 1980s. When 3,412 of the participants showed up for their physicals and lab tests between 2011 and 2013, they had reached ages 71 to 90 and did not have diabetes.
Prediabetes, however, was rampant. Almost three-quarters qualified as prediabetic, based on either their A1C or fasting blood glucose levels.
These findings mirrored a 2016 study pointing out that a popular online risk test created by the Centers for Disease Control and Prevention and the American Diabetes Association, called doihaveprediabetes.org, would deem nearly everyone over 60 as prediabetic.
In 2010, a C.D.C. review reported that 9 to 25 percent of those with an A1C of 5.5 to 6 percent will develop diabetes over five years; so will 25 to 50 percent of those with A1C readings of 6 to 6.5. But those estimates were based on a middle-aged population.
When Dr. Selvin and her team looked at what had actually happened to their older prediabetic cohort five to six years later, only 8 or 9 percent had developed diabetes, depending on the definition used.
A much larger group — 13 percent of those whose A1C level was elevated and 44 percent of those with prediabetic fasting blood glucose — actually saw their readings revert to normal blood sugar levels. (A Swedish study found similar results.)
Sixteen to 19 percent had died, about the same proportion as those without prediabetes.
“We’re not seeing much risk in these individuals,” Dr. Selvin said. “Older adults can have complex health issues. Those that impair quality of life should be the focus, not mildly elevated blood glucose.”
Dr. Saeid Shahraz, a health researcher at Tufts Medical Center in Boston and lead author of the 2016 study, praised the new research. “The data is really strong,” he said. “The American Diabetes Association should do something about this.”
It may, said Dr. Robert Gabbay, the A.D.A.’s chief scientific and medical officer. The organization currently recommends “at least annual monitoring” for people with prediabetes, a referral to the lifestyle modification programs shown to decrease health risks and perhaps metformin for those who are obese and under 60.
Now the association’s Professional Practice Committee will review the study, and “it could lead to some adjustments in the way we think about things,” Dr. Gabbay said. Among older people considered prediabetic, “their risk may be smaller than we thought,” he added.
Defenders of the emphasis on treating prediabetes, which is said to afflict one-third of the United States population, point out that first-line treatment involves learning healthy behaviors that more Americans should adopt anyway: weight loss, smoking cessation, exercise and healthy eating.
“I’ve had a number of patients diagnosed with prediabetes, and it’s what motivates them to change,” Dr. Gabbay said. “They know what they should be doing, but they need something to kick them into gear.”
Geriatricians tend to disagree. “It’s unprofessional to mislead people, to motivate them by fear of something that’s not actually true,” Dr. Lam said. “We’re all tired of having things to be afraid of.”
He and Dr. Sei Lee, a coauthor of the editorial accompanying the new study and a fellow geriatrician at the University of California, San Francisco, argue for a case-by-case approach in older adults — especially if a diagnosis of prediabetes will cause their children to berate them over every cookie.
For a patient who is frail and vulnerable, “you’re likely dealing with a host of other problems,” Dr. Lam said. “Don’t worry about this number.”
A very healthy 75-year-old who could live 20 more years faces a more nuanced decision. She may never progress to diabetes; she may also already follow the recommended lifestyle modifications.
Ms. Weinberg, now 69, sought help from a nutritionist, changed her diet to emphasize complex carbohydrates and protein, and began walking more and climbing stairs instead of taking elevators. She shed 10 pounds she didn’t need to lose. Over 18 months, her barely elevated A1C reading fell to 5.6.
Her friend Carol Jacobi, 71, who also lives in Los Angeles, got a similar warning at about the same time. Her A1C was 5.7, the lowest number defined as prediabetic, but her internist immediately prescribed metformin.
Ms. Jacobi, a retired fund-raiser with no family history of diabetes, felt unconcerned. She figured she could lose a little weight, but she had normal blood pressure and an active life that included lots of walking and yoga. After trying the drug for a few months, she stopped.
Now, neither woman has prediabetes. Although Ms. Jacobi did nothing much to reduce her blood sugar, and has gained a few pounds during the pandemic, her A1C has fallen to normal levels, too.