Adult female rats were fed, in addition to chow and water, a
carbohydrate source that differed in type (
glucose,
sucrose, or
polysaccharide), form (32%
solution,
powder, or gel), or taste (very sweet, minimally sweet, or bitter). A control group was fed only chow and water during the 40-day experiment. The groups fed the
glucose solution,
sucrose solution, or one of three
polysaccharide solutions (
Polycose,
maltose-
dextrin 10,
maltose-
dextrin 42) all overrate and gained more
body weight and fat than did the control group. The
carbohydrate solution groups did not differ in their total caloric intake,
weight gain, percent body fat, or basal
insulin level. The
polysaccharide groups, however, consumed more
carbohydrate than did the
sugar groups. The groups fed
glucose,
sucrose, or
Polycose in
powder form consumed less
carbohydrate and total calories, gained less weight and fat, and had lower
insulin levels than did the groups fed the saccharides in
solution form. The
powder groups did not reliably differ from the control group on these measures. Rats fed
Polycose in
solution form or in a solid gel form (32%
Polycose + 1%
agar) were similar in their
carbohydrate intake, total caloric intake,
weight gain, and percent body fat. Rats fed
Polycose solutions that were minimally sweet (32%
Polycose), sweet (0.2%
saccharin + 32%
Polycose), or bitter [0.05%
sucrose octa acetate (SOA) + 32%
Polycose] did not differ in their
Polycose intake, total caloric intake,
weight gain, or percent body fat. The results demonstrate that saccharide form is more important than saccharide type or taste in promoting
hyperphagia and
obesity in rats. The
Polycose gel findings further indicate that it is the water of hydration, not liquidity that is responsible for the
hyperphagia-inducing effect of
carbohydrate solutions.