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A. Janet Tomiyama (Cohort 7) Can Dieting Make You Fat?

For those stressing out about not fitting into this summer’s bathing suit, going on a calorie-restricted diet may just create additional worries and lead to more inches around the waistline. A new study finds that cutting calories triggers an increased production of the stress hormone cortisol, which is linked to the accumulation of belly fat.

The new study, “Low-Calorie Dieting Increases Cortisol,” is published online in the journal Psychosomatic Medicine, in advance of the May 14 print edition.
“Dieting involves not only resisting temptation, but also dealing with the physically negative feeling of being hungry and the repetitive hassles of continuously monitoring calories. The potential physical and mental harm caused by calorie-restricted dieting likely makes this type of dieting an ineffective weight-loss option for most people,” said A. Janet Tomiyama, Ph.D., lead author of the study and a Robert Wood Johnson Foundation Health & Society Scholarat the University of California, San Francisco.
Dieters may not realize that restricting their caloric intake puts physical stress on their bodies. They assume that their caloric restriction is not harmful, and often persevere in what may be a physically stressful diet, because they do not feel any mental pressure, according to the study. Chronic stress, in addition to promoting weight gain, has been linked with a host of negative health problems such as heart disease, cancer and diabetes.
At any given time, about 47 percent of the U.S. adult population is trying to lose weight. One of the most common weight-loss techniques is reducing the number of calories consumed. However, this type of weight loss tends to be short-term, with previous research indicating that 30 percent to 64 percent of dieters gain back more weight than they lost on the diet. 
People trying to manage their weight should not give up on controlling their food portions or stop paying attention to what types of food they eat, Tomiyama said. “Our findings reinforce the importance of exercise and making healthy food choices. These results should not be used as an excuse to abandon weight-control efforts, but rather encourage women to eat a balanced, healthy diet,” she said.
For the study, which was conducted at the University of California, Los Angeles, the dieting habits of 115 female participants were examined; complete follow-up data was available for 99 participants. The study focused on women because calorie-restricted dieting is higher in this population.
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The research findings presented here are those of the researcher and are not necessarily the views of the Robert Wood Johnson Foundation.