Study: Crash diets can lead to gallstones

measuring tapeExperts have long advised against extremely low-calorie diets, and a new study has found another reason to follow that advice: gallstones. While the risk was low, a Swedish study found that of 6,640 dieters those who followed a “crash diet”— 500 calories a day for up to 10 weeks, followed by reintroduction of normal food and exercise and healthy eating—were more likely to develop gallstones than those who ate a low-calorie diet of 1,200 to 1,500 calories followed by a weight-maintenance program.

Although the crash dieters lost more weight (about 28 pounds after three months) than the more moderate group (17 pounds), 48 developed gallstones requiring hospital care, compared with just 14 among the moderate dieters. And while the study didn’t reveal why one group was more likely to develop gallstones over another, the lead author hypothesized that rapid weight loss may affect salt and cholesterol in bile and the way the gallbladder empties, and the amount of weight lost and fat intake could also be factors. Experts recommend that very low-calorie diets be supervised by a medical professional.