Starch-induced overeating and overweight in rats: influence of starch type and form

In Experiment 1, adult female rats were fed, in addition to chow and water, a carbohydrate source that consisted of pure amylopectin corn starch or hydrolyzed corn starch (Polycose) in either a dry powder form or a hydrated gel form. Over the 30-day test periods, carbohydrate intake, total food intake, and body weight gain were greater with the Polycose than with the amylopectin, and greater with the gel form than with the powder form of the carbohydrates. The amylopectin gel produced overeating and overweight relative to a chow-fed control group, although the effects were less than that obtained with the Polycose gel. In a second experiment, test meals of the carbohydrate gels produced larger postmeal increases in plasma glucose than did the carbohydrate powders. There was no effect of carbohydrate type (amylopectin vs. Polycose) on the plasma glucose response. In Experiment 3, the addition of amylopectin to a Polycose gel reduced carbohydrate and total caloric intake. Both orosensory and postingestive factors may contribute to the differential food intake and body weight gains produced by the different types (Polycose vs. amylopectin) and forms (gel vs. powder) of carbohydrates.