Yo-yo diets yield gallstones in men -study

CHICAGO, Nov 28 (Reuters) Men who lose weight and gain it back in a pattern often called yo-yo dieting run a higher risk of developing gallstones later on, a study said.

When weight is regained after a loss, much of what is put back on is body fat, said the report yesterday from the University of Kentucky Medical Center in Lexington.

''Studies have shown that large swings of body weight, especially the phase of weight recovery, are particularly sensitive to the accumulation of body fat and to the development of metabolic abnormalities, including insulin resistance, and thereby may facilitate gallstone formation,'' said the report, which was published in the Archives of Internal Medicine.

Men in the group who had lost between 5 and 9 pounds and regained it ran a 21 per cent increased risk for gallstones compared to those who had a steady weight. The risk was 38 per cent higher for those who lost and regained between 10 and 19 pounds and 76 per cent higher for those who lost and regained 20 pounds or more.

The number of times the subject's weight went up and down also made the risk higher.

In addition, certain hormones in the blood have been shown to be higher in people whose weight bounces back and forth than in those who maintain a steady weight, which could also contribute to gallstone risk, the report said.

The findings came from a multiyear study involving more than 24,000 male health professionals who provided information about weight fluctuations between 1988 and 1992 and were then queried on their health periodically for the following 10 years.

Gallstones are solid masses of cholesterol, bile and calcium salts that form in the gall bladder and are common among adults in Western countries. Obesity in general increases the risk for their development. Only about 20 percent of such stones cause problems, usually when they become stuck in the duct leading from the gallbladder, causing intense pain.

REUTERS SP PM1041