A composition and method is provided for promoting weight loss in a mammal by feeding effective amounts of at least three nutrients selected from L-carnitine, chromium, Vitamin A, and a source of carbohydrates selected from a low glycemic index grain. The composition preferably includes all four nutrients and may be fed in an amount of 1.0 to 10.0 mg of L-carnitine per kilogram of body weight per day, from about 5.0 to about 15.0 micrograms of chromium per kilogram of body weight per day, and from about 1.0 to 3.0 grams of starch per kilogram of body weight per day.