Chronic dieting can lead to major weight gain
NEW YORK, (Reuters Health) -- The dieter's nightmare is true -- weight-loss attempts increase the risk of major weight gain in the long term, researchers from Finland report.
And parents are partly to blame, although they can't help it -- genes passed from parents to children play a role in weight gain, according to the study findings.
Young adult men and middle-aged women who diet are at risk of subsequently gaining more than 10 kg (22 pounds) over the next 15 years, putting them at increased risk of developing diabetes, high blood pressure and heart disease, the investigators found.
"We conclude that weight-loss attempts appear to increase the risk of long-term major weight gain in adults," write lead author Maarit Korkeila of the University of Helsinki, and colleagues in Finland.
They add, "much of the observed relation between weight-loss attempts and major weight gain can be attributed to a familial predisposition to gain weight, which ultimately overwhelms even ambitious weight-loss attempts."
Average weight gain was only weakly linked with dieting attempts, suggesting that it is possible for some people to maintain weight loss over the long term, the authors note.
The researchers followed 3,536 men and 4,193 women aged 18 to 54 for a period of 6 to 15 years. They recorded weight, weight-loss attempts, and possible confounding factors such as smoking, alcohol use, educational level, social class and marital status, at the outset and again at two points over the course of the study. Information was obtained through self-reported questionnaires.
The investigators also examined family factors in 1,705 sets of twins who had different dieting histories when the study began.
According to the results, almost all normal weight subjects who attempted to diet when the study began gained weight over 6 to 15 years. Men between 18 and 29 years and women between 30 and 54 years were at the greatest risk regardless of smoking, alcohol use, social class, educational level and marital status.
About 30% of US adults report that they are dieting at any given time, in part because weight loss is seldom maintained over the long term, the authors write in the December issue of the American Journal of Clinical Nutrition.
Their research confirms the results of other recent studies demonstrating that a history of dieting predicts weight gain in American adults. "Our findings agree with prospective information showing that dieting behavior may be related to the risk of weight gain," they conclude.
SOURCE: American Journal of Clinical Nutrition 1999;70:965-973.
