Diet, physical activity, and gallstones--a population-based, case-control study in southern Italy.

BACKGROUND Gallstones are a highly prevalent condition; however, the nutritional and lifestyle risk factors of this disease are not well understood. OBJECTIVE We evaluated the association between diet, physical activity, and incident cases of gallstones diagnosed by ultrasound in a population-based, case-control study. DESIGN One hundred patients with newly diagnosed gallstones and 290 randomly selected control subjects without gallstones were enrolled in the study. The presence of gallstones was determined by ultrasonography. Both patients and control subjects completed a questionnaire about their usual diet and physical activity for the 12 mo before the ultrasonography. The association between diet and physical activity and risk of gallstone formation was analyzed by using multiple logistic regression. RESULTS Body mass index and intake of refined sugars were directly associated with risk of gallstone formation, whereas physical activity, dietary monounsaturated fats, dietary cholesterol, and dietary fibers from cellulose were inversely associated with risk of gallstone formation. Saturated fats were a risk factor for gallstone formation and the association appeared to be stronger for men than for women. CONCLUSION These findings suggest that a sedentary lifestyle and a diet rich in animal fats and refined sugars and poor in vegetable fats and fibers are significant risk factors for gallstone formation.