Why don’t diets work? And what makes most people who’ve lost weight on such diets relapse? With obesity rates reaching record levels across the country, experts in public health and nutrition are intent on finding answers to such questions in order to help people change their eating habits for the longterm and improve their health.
The researchers who run the Dieting, Stress and Health (DISH) Lab in UCLA's psychology department are looking for those answers as well — and more — but from a wide-ranging, multidisciplinary perspective that takes into considerationo emotional eating, psychological stress, cultural and racial differences, and even cellular aging.
"Any solution will require multidisciplinary science that integrates behavior and biology," said UCLA psychologist A. Janet Tomiyama, who runs the lab where researchers draw knowledge from not just psychology, but biology, medicine, public health, gerontology and sociology, among other disciplines. "There are so many initiatives and interventions, for example, to reduce stress eating. How can we get people not to eat when they’re stressed? I think my work has implications for that."
One question that Tomiyama is hoping to answer is whether comfort food actually does give comfort and relieve stress.
Tomiyama, an assistant professor who received her Ph.D. in social and health psychology at UCLA in 2009 and became a Robert Wood John Foundation Health and Society Scholar at UC San Francisco and UC Berkeley, is measuring whether eating comfort food can dampen down your biological stress system, resulting in lower levels of cortisol, the stress hormone. She’s also measuring levels of oxidative stress, which indicates wear and tear at the cellular level.
"If not eating food makes me feel badly, then eating food must make me feel good," surmised Tomiyama, who admits to being a foodie who loves to eat. "As a stress researcher, I realized that I can empirically measure whether food can or cannot relieve stress."
Psychologist Janet Tomiyama
If her research shows that comfort food can bring down stress levels, then it may be that food, which has gotten a bad rap lately, isn’t inherently evil. "It may help you in the short-term even though it may affect your health in the long-term. You have to decide what’s more important for you," she said.
Taking this a step further, if Tomiyama can find what kind of comfort food people most enjoy and what works best at relieving stress — sweet, salty or high fat content in the right combination — can food scientists then engineer a healthier version of that? "In other words, can we get the same comforting effects out of food without the negative health effects? I think we’ll get there someday," she said.
And then there’s the question of whether just the stigma of being overweight causes such stress that health problems result. "We know that racial stigma, gender discrimination and homophobia all do negatively affect the body. But no one has studied weight stigma. And I believe that weight stigma is now, in fact, more pervasive than racial stigma, sexism or homophobia. People assume that being obese is in itself unhealthy. But what if part of what’s unhealthy about being overweight is the stigma that people are encountering?"
Currently, Tomiyama and her graduate students are doing the first psychological assessment of people who voluntarily put themselves on low-calorie diets for years — on average, 10 years. She is studying members of two organizations, the Calorie Restriction Society and the CR Way, people who believe they can extend their lives and stay healthy by restricting their diets typically to between 1,200 to 1,600 calories a day.
It is the largest study of its kind, said Tomiyama. She’s looking for answers to two questions: Why are they successful at restricting calories in their diet for such an extended period of time. "And can we harness what they are doing to help others? They are unique along several psychological dimensions," she said.
To find out whether these calorie restrictors are actually extending their lifespans, Tomiyama is looking at a number of aging markers in their very lean bodies, including the length of the telomeres in their cells. "As organisms age, telomeres, the protective structures at the tips of chromosomes, get shorter until they reach a critical point," said the psychologist. "And then the cells go into an arrested state."
In worms, for example, calorie restriction in their diets can cause them to live four times longer than their counterparts living in the wild, Tomiyama said. "So does calorie restriction in humans also extend lifespan?"
What she hopes to learn may ultimately shift the focus off dieting and instead harness the power of food in other ways to promote health.