Joan Dye Gussow, a nutritionist and educator who was often referred to as the matriarch of the “eat locally, think globally” food movement, died on Friday at her home in Piermont, N.Y., in Rockland County. She was 96.

Her death, from congestive heart failure, was announced by Pamela A. Koch, an associate professor of nutrition education at Teachers College, Columbia University, where Ms. Gussow, a professor emeritus, had taught for more than half a century.

Ms. Gussow was one of the first in her field to emphasize the connections between farming practices and consumers’ health. Her book “The Feeding Web: Issues in Nutritional Ecology” (1978) influenced the thinking of the writers Michael Pollan, Barbara Kingsolver and others.

“Nutrition is thought of as the science of what happens to food once it gets in our bodies — as Joan put it, ‘What happens after the swallow,’” Ms. Koch said in an interview.

But Ms. Gussow beamed her gimlet-eyed attention on what happens before the swallow. “Her concern was with all the things that have to happen for us to get our food,” Ms. Koch said. “She was about seeing the big picture of food issues and sustainability.”

Ms. Gussow, an indefatigable gardener and a tub-thumper for community gardens, began deploying the phrase “local food” after reviewing the statistics on the declining number of farmers in the United States. (Farm and ranch families made up less than 5 percent of the population in 1970 and less than 2 percent of the population in 2023.)

As Ms. Gussow saw it, the disappearance of farms meant that consumers wouldn’t know how their food is grown — and, more critically, wouldn’t know how their food should be grown. “She said, ‘We need to make sure we keep farms around so we have that knowledge,’” Ms. Koch said.

Marion Nestle, a nutritionist and public health advocate, said that Ms. Gussow “was enormously ahead of her time,” adding, “Every time I thought I was on to something and breaking new ground and seeing something no one had seen before, I’d find out that Joan had written about it 10 years earlier.”

“She was a food systems thinker before anyone knew what a food system was,” Ms. Nestle said, referring to the process of producing and consuming food, including the economic, environmental and health effects. “What she caught on to was that you couldn’t understand why people eat the way they do and why nutrition works the way it does unless you understand how agriculture production works. She was a profound thinker.”

Ms. Gussow was not one to shy away from a food fight. She talked about energy use, pollution, obesity and diabetes as the true price consumers were paying for what they consumed at a time when this point of view did not win friends or influence people. She was labeled “a maverick crank,” as a New York Times profile noted in 2010.

But Ms. Gussow’s gainsaying later became gospel.

“Joan was one of my most important teachers when I set out to learn about the food system,” Mr. Pollan, the author of “The Omnivore’s Dilemma” and “In Defense of Food: An Eater’s Manifesto,” wrote in an email. “When I asked her what nutrition advice her years of research came down to, she said, very simply, ‘Eat food.’”

“After a slight elaboration,” Mr. Pollan continued, “this became the core of my answer to the supposedly very complicated question about what people should eat if they are concerned about their health: ‘Eat food. Not too much. Mostly plants.’” (That answer also appeared in the opening lines of “In Defense of Food.”)

Joan Dye was born on Oct. 4, 1928, in Alhambra, Calif., to Chester and M. Joyce (Fisher) Dye. Her father was a civil engineer.

After graduating from Pomona College in 1950, she moved to New York City, where she spent seven years as a researcher at Time magazine. In 1956, she married Alan M. Gussow, a painter and conservationist.

Ms. Gussow made a disquieting observation when she and her husband, who had recently become parents, moved to the suburbs in the early 1960s and began shopping at the local grocery stores. “You know,” she said in an interview years later, “we’d gone from 800 items to 18,000 items in the supermarket, and they were mostly junk.”

Ms. Gussow went back to school in 1969 and received a doctorate in nutrition from Columbia University. In 1972 she published the article “Counternutritional Messages of TV Ads Aimed at Children” in the Journal of Nutrition Education. Her research showed that 82 percent of the commercials that aired over the course of several Saturday mornings were for food — most of it nutritionally suspect.

She had earlier testified to a congressional committee on the subject. Futilely, as it turned out.

But in a 2011 interview posted on Civil Eats, a news site focused on the American food system, Ms. Gussow pointed to at least small portions of progress.

“I must say that compared to the reception my ideas got 30 years ago, it’s quite astonishing the reception they’re getting now,” she said. “I am excited to see the kinds of things that are going on in Brooklyn, for example. People are butchering meat, raising chicken.” But, she added, “whether or not there’s going to be sea change in the whole system is so hard to judge.”

To be sure, Ms. Gussow practiced what she preached. She began growing backyard produce in the 1960s, initially as a way to cut costs and then as a way of life. When she and her husband relocated to Piermont in 1995, Ms. Gussow established another garden, one that extended from the back of their house down to the Hudson River.

She repeated the grueling process in 2010, when, months after her 81st birthday, a storm surge ripped the raised beds out of the ground and buried all the vegetables that made up the family’s year-round food supply under two feet of water.

“I found myself quite numb — not hysterical as I might have expected,” she wrote on her website after assessing the damage. “I think it’s age.”

Alan Gussow died in 1997. Ms. Gussow is survived by two sons, Adam and Seth, and a grandson.

In her book “Growing, Older: A Chronicle of Death, Life, and Vegetables” (2010), Ms. Gussow expressed the fervent hope that she would not be remembered as “a cute little old lady.”

“I have posted on my bulletin board the comment I found somewhere,” she wrote. “‘The day I die, I want to have a black thumb from where I hit it with a hammer and scratches on my hands from pruning the roses.’”