Why Do Diets Fail?

The concept of dieting is easy—limit caloric intake and the pounds will drop. Why then are most dieters unsuccessful? Diana Thomas, director of the Center for Quantitative Obesity Research at Montclair State, has a theory. "The results of diet-induced weight loss are modest and it is suspected that patient dietary adherence is largely responsible," said the professor of Mathematical Sciences. In other words, we don't stick to the diet plan. And with more than 20 percent of the American population affected by obesity and its comorbidities, non-adherence to dietary prescriptions will prevent individuals from achieving normal weight and resulting positive health outcomes.

three people on scales Current objective methods for assessing dietary intake require extensive clinical visits or subject confinement. "Both methods are expensive and not feasible for extended periods of time," Thomas explains. Instead, she proposes an affordable, non-invasive, accurate method that uses mathematical models to monitor subject intake during weight loss. "We propose to meet this need through application of a validated energy balance model."

Thomas believes the proposed model, developed in collaboration with a team of experienced obesity researchers and mathematicians, can change current practices for determining patient dietary adherence and provide vital information for understanding the obesity problem in the nation. Her research has received more than $300,000 in funding from the National Institutes of Health (NIH).

Thomas is no newcomer to this area of research. She is a co-investigator on an NIH project, "Expecting Success: Personalized Management of Body Weight during Pregnancy," which received funding from the Pennington Biomedical Research Center. Last year she co-authored a study that linked a decrease in workplace physical activity to the obesity epidemic.