September 1, 2004

Penn Study Shows Dieting Not Associated With Binge Eating or Depression in Obese Women

(Philadelphia, PA) – Concern about possible adverse effects of dieting has prevailed since the 1950s when a study drastically cut the calorie intake of average-weight volunteers and found that many developed depression and binge eating. Experts today believe that aggressive dieting in young females may be associated with psychological or physical deprivation that contributes to binge eating, bulimia nervosa, and related eating disorders.

Now a study by researchers in the Department of Psychiatry at the University of Pennsylvania School of Medicine has shown that sensible dieting does not appear to precipitate binge eating, depression, or other negative behavioral consequences in obese women undergoing weight reduction. The study appears in the September issue of the American Journal of Clinical Nutrition and is the first designed specifically to determine whether dieting is associated with ill effects. "These findings should reassure overweight and obese adults who are trying to lose weight, as well as health professionals who recommend dieting," said Thomas Wadden, PhD, lead investigator and director of Penn's Weight and Eating Disorders Program.

The Penn study examined 123 women with a mean age of 44 years and weight of 214 pounds, who were determined by an examiner to be completely free of binge eating prior to the start of treatment. The women were randomly assigned to one of three dietary interventions:

(1) a meal replacement that prescribed 1000 calories/day during the first 12 weeks and included the consumption of four liquid shakes (OPTIFAST 800)/day.

(2) a conventional diet of self-selected foods with a goal of 1,200 - 1,500 calories/day.

(3) a non-dieting approach that encouraged patients to avoid calorie restriction in favor of paying closer attention to their hunger and fullness levels.

All women received group treatment for 40 weeks and participated in a six-month follow-up evaluation.

At week 40, women in the meal replacement group had lost 24 pounds, the conventional dieters had lost 18 pounds, and those in the non-diet group had lost 2 pounds. Women in the two dieting groups reported significantly greater reductions in symptoms of depression at week 40, than those in the non-dieting group. Participants in all three groups reported significant reductions in hunger.

Binge eating was assessed at weeks 9, 20, 28, 40, and 65 of the study. At week 28, there was a very small but statistically significant increase in reports of binge eating in women in the meal replacement group. The increase, however, declined by week 40 and there were no significant differences between the three groups in the number of binge episodes at any of the other four assessment periods, including the 6-month follow-up evaluation. "Our findings indicate that dieting, including the use of meal replacements, presents few risks of binge eating or depression in obese women who seek to lose weight by using sensible methods," commented Wadden. "This conclusion, however, should not be interpreted as a denial of the potential perils of aggressive dieting in adolescent girls and young women of average weight who pursue an ever thinner ideal," he added.

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PENN Medicine is a $2.7 billion enterprise dedicated to the related missions of medical education, biomedical research, and high-quality patient care. PENN Medicine consists of the University of Pennsylvania School of Medicine (founded in 1765 as the nation’s first medical school) and the University of Pennsylvania Health System (created in 1993 as the nation’s first integrated academic health system).

Penn’s School of Medicine is ranked #3 in the nation for receipt of NIH research funds; and ranked #4 in the nation in U.S. News & World Report’s most recent ranking of top research-oriented medical schools. Supporting 1,400 fulltime faculty and 700 students, the School of Medicine is recognized worldwide for its superior education and training of the next generation of physician-scientists and leaders of academic medicine.

Penn Health System is comprised of: its flagship hospital, the Hospital of the University of Pennsylvania, consistently rated one of the nation’s “Honor Roll” hospitals by U.S. News & World Report; Pennsylvania Hospital, the nation's first hospital; Presbyterian Medical Center; a faculty practice plan; a primary-care provider network; two multispecialty satellite facilities; and home health care and hospice.

This release is available online at http://www.uphs.upenn.edu/news/News_Releases/sep04/dietingeffects.htm