A cacophony of slapping noises filled the food lab at the High School for Environmental Studies in Manhattan one afternoon in late October.

“Think of all the hands that have done this for thousands of years,” said Andrew Margon, an English teacher, as his students energetically pummeled lumps of corn masa into tortillas.

The students were taking a cooking class as part of Food Ed., an interdisciplinary curriculum developed by the Stone Barns Center for Food and Agriculture, a nonprofit farm and educational center based near Tarrytown, N.Y., which also has a partner high-end restaurant. The course offers students a whirlwind tour of how food gets grown, marketed and consumed. Food Ed., which was introduced five years ago into a handful of schools in the New York area, is now offered as an elective in 37 high schools nationwide. Additional schools are planning to start the program soon.

“We don’t aim to change the way students eat in line with a particular dietary prescription,” said Lindsey Dayton, the senior manager of the Food Ed. program. “We want to help them think critically about the way nutrition intersects with culture as well as the environment and farming. We want our students to understand how eating makes them a part of the natural world and not separate from it.”

It may be working.

“When I look at my plate now,” said Marco Ricci, 16, one of Mr. Margon’s students, “I think about the effort that goes into it, the dirt and all the nutrients it needs in the soil. It’s amazing that this salad in front of you is made of so many different things grown in so many different places in so many different ways.”

Students are also learning about the plight of farm workers who are exposed to toxic agricultural chemicals and about the millions of people in the United States who are undernourished or don’t have access to healthy food in their communities.

As part of a unit on food waste, Mr. Margon’s class will gather donations of “seconds,” slightly flawed or outdated produce, from farmers’ markets around the city and use it to prepare lunch for 100 homeless New Yorkers at the end of the school year in June.

“There are lots of school garden programs, mostly in elementary schools. And there are also some great food courses in colleges,” said Danielle Nierenberg, the president of the nonprofit group Food Tank, which calls itself “a think tank about food.” But food is no longer routinely taught as a separate subject to high schoolers, she said.

“We are educating kids to pass tests; we’re not educating them to live healthy lives,” Ms. Nierenberg said.

Abby Franks teaches Food Ed. at Morey FlexTech, a high school in Shepherd, Mich., set in the middle of corn and soy fields. Ms. Franks is also concerned about the impact of fast food culture on her students. But it’s not enough for them to simply rethink their personal diets. She also wants students to scrutinize the industrial agricultural system that surrounds them.

“If they are eating a burger, I hope they’ll ask, ‘I wonder how this cow was treated, what impact did it have on the environment, what is my own imprint on the world,’” Ms. Franks said. “I want them to move beyond passively consuming and to become thoughtful about the food they eat.”

Her class is currently evaluating the pros and cons of an industrial pig operation that will be opening in their town.

Ms. Franks is revising the ambitious sample menus that Stone Barns provides to focus on less exotic foods like tacos that are familiar to her students. But the students’ palates are hardly timid: They cooked up some culinary-grade insects as part of a lesson on “taboo foods.”

Those who tried them preferred fried meal worms, which resembled crispy McDonald’s fries, Ms. Franks reported, over flying ants, whose acidic sourness turned out to be an acquired taste.

Veronica Lopez, a science teacher at César E. Chávez Learning Academies in San Fernando, Calif., who was trained in the Food Ed. curriculum at Stone Barns last July, helped her class make sopes de chapulines, a kind of grasshopper tostada with beans and vegetables, a traditional delicacy in southern Mexico.

Ms. Lopez decided to teach a special theme about corn, given its historical importance in Mexico and Central America, where many of her students’ families come from. She called Ms. Dayton at Stone Barns for advice.

“We talked about how corn has been maligned, and students are hearing that corn is bad, it isn’t healthy,” Ms. Dayton said. She advised Ms. Lopez to focus on corn’s traditional role and nutritional value as a whole grain.

“When they are making connections with plants, with food and with nature, it builds relationships, relationships between them and what they are eating,” Ms. Lopez said. “When you have a relationship with your food, you just naturally want to put things that are healthier inside yourself.”

For Mr. Margon’s class, the highlight of the semester was a field trip on a sunny Friday in November to Stone Barns, a 400-acre agricultural complex with pigs, cows and turkeys, as well as experimental growing areas where new crop varieties are tested.

In addition to preparing a traditional Salvadoran meal entirely from ingredients produced on the Stone Barns farm and feeding the Red Wattle cross pigs with the leftovers, the students nibbled their way through a walking tour of the property sampling wild sassafras root, kale and other produce.

Carolina Saavedra, a Stone Barns employee who is also the chef at La Morada, a Oaxacan restaurant and hub of food activism in the South Bronx, offered the students snippets of a freshly harvested cabbage leaf. “How is this cabbage different from what you have tasted before?” she asked.

“It tastes better, it’s sweeter,” said Angel Guerra, an 11th grader.

“That’s right,” Ms. Saavedra said. “The colder it gets, the more sugar these plants are producing in order to protect themselves so they can survive through winter. It is a special cold-tolerant variety.”

Selecting cold-tolerant plants is essential if you want to grow food outside year-round, said Jessica Galen, the senior communications manager at Stone Barns.

“Just think of what it would mean if we had a robust regional food culture that incorporated what works in our climate during all seasons, instead of having to ship most of our produce in from places like California,” she said.

The point of Food Ed. is not just to encourage some high schoolers to eat more healthful food, Ms. Galen said. It is to educate students who can help to create a healthier food system for all of us.

“When young people learn how to ask these kinds of questions,” she said, “they become empowered consumers who can make the changes that we need to see.”