"Weight cycling" -- intentionally losing weight then gaining it all back -- may increase men's risk for gallstones, a University of Kentucky Medical Center study finds.

Researchers analyzed data from nearly 25,000 men who took part in the Health Professionals Follow-up Study. The men provided information about any weight fluctuations occurring between 1988 and 1992, and whether they developed gallstones between 1992 and 2002.

The men were grouped as: weight maintainers (those who remained within five pounds of their initial weight between 1988 and 1992); light weight cyclers (a maximum weight loss of between five and nine pounds); moderate cyclers (weight loss between 10 and 19 pounds); and severe cyclers (weight loss of 20 pounds or more).

Overall, there were over 1,200 cases of symptomatic gallstones between 1992 and 2002.

Compared to weight maintainers, light cyclers had a 21 percent increased risk of gallstones, moderate cyclers had a 38 percent increased risk, and severe cyclers had a 76 percent increased risk.

The study was published in the Nov. 27 issue of the journal Archives of Internal Medicine.

There are a number of likely factors contributing to the association between weight cycling and gallstones, the study authors said. They noted that when a person loses and then regains weight, much of the regained weight is made up of body fat.

"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," the researchers wrote.