"Yo-yo" dieting, the cycles of weight loss and weight gain endured by millions of Americans, including many who are not overweight, can have serious and even fatal consequences, a new study has shown.
The study, being published today in the New England Journal of Medicine, reveals that repeated changes in weight, irrespective of a person's initial weight, are linked to an increased death rate overall and to at least doubling the risk of dying of heart disease.
Dr. Kelly D. Brownell, a psychologist and weight specialist at Yale University who directed the study, said the findings suggest that the harmful effects of weight cycling might be equal to the risks of simply remaining obese, which has been found to double the chances of dying.
The findings are based on an analysis of weight fluctuations and their consequences observed over 32 years among 3,130 men and women who participated in the Framingham Heart Study in Massachusetts.
The risk of heart disease, death from heart disease and death from all causes was 25 percent to 100 percent higher in the group with the most weight fluctuation, regardless of each person's initial weight, blood pressure, smoking habits, cholesterol level and level of physical activity.
In another study, not yet published, David Williamson of the federal Centers for Disease Control in Atlanta found that people who repeatedly lose and regain more than 25 pounds have a higher risk of dying prematurely than people who smoke cigarettes.
Based on those and related findings, Dr. George Blackburn, an obesity specialist at Harvard Medical School, said that "current federal guidelines telling everyone who is fat to get unfat should go back to the drawing boards, since 95 percent of dieters are unable to keep the weight off."