In 1982, Harvard Medical School psychiatrist Anne E. Becker was still an undergraduate at Radcliffe when she traveled to Fiji for a summer of anthropology fieldwork.

What struck her about this South Pacific island nation — and has in many research trips since — was “the absolute preoccupation with food and eating,” she said. “Family and social life really revolve around food. … It’s all about food, all the time.”

In a March 11 lecture at Radcliffe Gymnasium, Becker described “the rhetoric of encouragement” older women use to draw passersby into lavish meals. Afterwards, she said, eaters “unbutton, they unzip, they just lie down where they are. … That’s a good meal in Fiji.”

The centrality of food, in part, is a cultural artifact of a traditional economy based on the shifting fortunes of subsistence agriculture. Who knew when the next run of fish would come, or how good the crops would be?

So prosperity has traditionally been associated with food, and with hefty figures. In women especially, Fijians “appreciate large, robust bodies,” said Becker.

But that ideal body type is now on a collision course with the Western ideal that equates beauty with thinness. This clash of cultures has affected adolescent girls most deeply, she said, and has engendered mental health implications.

Since that first trip to Fiji, Becker has earned a raft of Harvard degrees: an A.B. in 1983 (when she was awarded Radcliffe’s Captain Jonathan Fay Prize for outstanding scholarly work); an M.D./Ph.D. in 1990; and a Sc.M. (in epidemiology) in 1995.

Today she’s an associate professor of anthropology and psychiatry at Harvard Medical School, and director of the Eating Disorders Clinical and Research Program at Massachusetts General Hospital.

Inspired by what is now more than two decades of research in Fiji, Becker is a student of eating habits and self-image in an ancient native culture now beset by the pressures of modernity. She is the author of “Body, Self, and Society: The View from Fiji” (University of Pennsylvania Press, 1995).

Becker oversaw a 1995-98 study that measured the effect of television on cultural norms. (Television was only catching on in Fiji in 1995. A decade before, even electricity was rare.)

The results were startling. In 1995, without television, girls in Fiji appeared to be free of the eating disorders common in the West. But by 1998, after just a few years of sexy soap operas and seductive commercials, 11.3 percent of adolescent girls reported they at least once had purged to lose weight.

To illustrate this rapid transformation of ideals, Becker quoted from the 1998 interviews. “I want their body,” said one girl of the Western shows she watched. “I want their size.”

By the glow of television, young girls in Fiji “got the idea they could resculpt their lives,” said Becker — but they also began to “think of themselves as poor and fat.”

Television brought with it “a social storm” of many dimensions, she said. For one, it dislocated traditional clans. Becker showed a picture of the chief’s family in their living room. To one side was a television, and on the other was a treadmill.

Television and other Western influences also stimulated an appetite for consumer goods hardly anyone could afford. Becker gave an example: To feed his family one meal at McDonald’s, a farmer would have to grow and cut one ton of sugar cane.

The changing social environment also took its toll on mental health. In 2007, Becker started a school-based study within one wedge-shaped section of Viti Levu, Fiji’s main island. More than 520 girls filled out questionnaires, and 300 consented to interviews.

Becker found that disordered eating habits were “alive and well in Fiji,” with 45 percent of girls reporting they had purged in the last month. (In some cases, they got traditional herbal purgatives from their mothers.)

Ironically, the same girls sometimes used appetite stimulants, she found. They feared what in Fijian is called macake, a disorder that suppresses the appetite — inviting the thinness disparaged by traditional culture.

Becker’s study also revealed a dissonance between the reality of the girls’ lives (poor and agrarian) and their expectations (rich and cosmopolitan). Nearly 80 percent of the girls said they planned on professional careers. That included being an airline hostess. “They only want thin girls,” one respondent said.

But there was a back story to this overarching narrative, said Becker: violence and despair. Among the girls interviewed, nearly 25 percent reported thoughts of suicide in the year before. This frame of mind often followed beatings; 15 percent of the girls reported such physical attacks.

At Radcliffe, Becker is working through her recent Fiji data to unpack the social context of eating disorders and suicidal ideation among adolescent girls. One question is natural, she said: What can be done?

In the search for what she called “pragmatic and moral solutions,” Becker said it does not help that Fiji’s mental health infrastructure is deficient. New Zealand and Australia, neighboring Pacific nations, set aside an average of 10 percent of health budgets for mental issues. Fiji sets aside 1.7 percent.

Schools might take on a mental health role, but they are struggling, said Becker. Intervention with parents is a limited option. For one, many mothers support their daughters wanting to be thin. It’s a way of supporting their ambition of escaping the island for a better life.

Becker is struggling for the answers. Multiple approaches, she said — epidemiology, ethnography, and clinical medicine — may shake loose the key.

In the end, it may be beyond one researcher to represent a distant people’s authentic experiences. Becker quoted the postmodern anthropologist Renato Rosaldo: “Good ethnographers still have limits and their analyses always are incomplete.”