Some of Alison Field’s earliest epidemiological observations were made on the job in the late 1980s as a Jenny Craig consultant.

“It was amazing to me how many programs people had been on trying to lose weight,” said Field, who will join the Brown University faculty in December as the new chair of epidemiology. “Everyone had tried everything, which made me think we needed to move toward prevention.”

The experience motivated Field, who had taken just a couple of public health classes as a psychology student at the University of California–Berkeley, to seek a master’s degree at Harvard. When a doctoral position on eating disorders opened up, she seized the opportunity.

As familiar as weight concerns and eating disorders seem to be, given Americans’ struggles with eating and weight, there are a lot of fundamental gaps in knowledge, especially regarding children and young adults. Drawing on rich data sources, including some that she helped create, Field has been working for more than two decades not only to understand the behavioral origins and health outcomes of these problems but to inform and improve the medical and public health approach to them.

For example, the same recommendations are generally given to all patients in an obesity clinic, but they don’t work equally well for everyone. Field is working to identify specific subtypes of obesity to make treatment more personalized and effective.

“We’re sort of in the infancy,” she said. “In cancer research we have precision medicine. We look at diseases such as melanoma, which used to be a death sentence. But now we know that for specific subtypes with specific genetic signatures there are targeted therapies that are very effective.”

By better classifying and subtyping obesity and eating disorders, Field hopes to help sharpen the field’s attention on where research needs to be done and to make prevention and treatment more specific and effective.

Earlier this year Field, who has helped redefine eating disorder diagnostic criteria, cheered as psychiatrists recognized binge eating disorder for the first time with the publication of DSM-V. Binge eating disorder is much more common than the better known disorders anorexia and bulimia nervosa, but it hadn’t been similarly recognized. Now there may be more research, recognition by primary care doctors and specialists, and improved treatment.

As Field has worked to inform eating disorder and obesity prevention and treatment, she has also delved deeply into studying how they arise and how they affect patients, especially children. As a postdoc at Harvard in 1996 she helped launch the Growing Up Today Study, a long-term study of almost 17,000 boys and girls living throughout the United States. She’s been studying that dataset, a more recent similar study launched in 2004, and other sources to make key discoveries ever since. Overall, she has co-authored more than 100 peer-reviewed papers in these areas.

Last year in Obesity, for example, she documented the major role that sports drinks have in weight gain among teens and young adults. With slumping soda sales, beverage companies have marketed sports drinks as part of a healthy lifestyle, Field said. But the drinks, which are about as sugary as soda because they come in multi-serving bottles, were designed for extremely active athletes like marathoners or football players. Many kids who aren’t engaging in that level of activity are consuming sports drinks and gaining weight because the drinks they perceive as a healthier choice have similar calories as Coke and Pepsi.

Marketing and media are not the only influences. Peers and parents matter, too, at least while kids are young. Exactly what effect they have is an urgent question. One of Field’s findings is that dads may matter more than moms in creating weight concerns in kids.

“Boys and girls who believe that their weight is important to their dads, regardless of their weight, are more likely to become very weight concerned,” she said.

Along those lines, Field and her colleagues have also found that parents shouldn’t feature weight (or shame) when encouraging a change in eating behavior.

“Some of the interventions that work best for kids focus on changing the behavior but not changing it for weight,” she said. “You are changing it for health, you’re changing it for more energy, or for fun with your friends.”

In her 20 years at Harvard since earning her Sc.D., Field has risen to become a professor of both epidemiology and pediatrics. She believes in working across disciplines and sees coming to Brown as a great opportunity to do more of it.

“That is how we have to move science forward,” she said. “That’s very possible at Brown.”

That goes not just for research, she said, but also for training and teaching. Field said she’s particularly excited that undergraduates can concentrate in public health at Brown. She “stumbled into public health” after a couple of classes and the Jenny Craig job, but here she hopes she’ll see many young scholars sign up to improve health, right from the start.