Reduced risk of liver-function-test abnormalities and new gallstone formation with weight loss on 3350-kJ (800-kcal) formula diets.

Weight loss in obese subjects ingesting very- low-energy (VLE; < 25 10 kJ/d), low-fat ( � 1 g/d) formula diets is associated with liver-function-test abnormalities and gallstone formation. It is unknown whether these abnormalities develop during treatment with diets higher in energy and fat. We pro- spectively studied liver-function tests and gallstone formation in 73 obese patients ingesting �3500 LI and 15-25 g fat daily for 10 wk. Two of 53 patients completing the protocol developed ultrasonographic gallstones during weight loss, a rate substan- tially lower than that observed with VLE diets. Trend analysis demonstrated significant increases in AST and ALT activities, but changes were less than those observed with VLE diets. Pa- tients who developed gallstones had a significantly greater weight loss rate and larger increases in AST and ALT than did nonstone- forming patients. These results suggest that the risk of developing hepatobihiary abnormalities with dieting is lowered when sub- jects ingest greater amounts of energy and fat than that admin- istered in earlier VLE-diet studies. Our results also highlight po- tential risk factors and markers of new gallstone formation. Am J C/in Nutr 1994;60:249-54.