Search

Although high protein and low glycemic index (GI) foods are thought to promote satiety, little is known about the effects of GI, protein, and their interaction on hunger and energy intake several hours following a mixed meal. This study investigated the long term effects of GI, protein, and their combined effects on glucose, insulin, hunger, and energy intake in healthy, sedentary, overweight, and obese adults (BMI of 30.9 ± 3.7 kg/m(2)). Sixteen individuals participated separately in four testing sessions after an overnight fast. The majority (75%) were non-Hispanic Blacks. Each consumed one of four breakfast meals (high GI/low protein, high GI/high protein, low GI/low protein, low GI/high protein) in random order. Visual analog scales (VAS) and blood samples were taken at baseline, 15 min, and at 30 min intervals over 4 h following the meal. After 4 h, participants were given the opportunity to consume food ad libitum from a buffet style lunch. Meals containing low GI foods produced a smaller glucose (P < 0.002) and insulin (P = 0.0001) response than meals containing high GI foods. No main effects for protein or interactions between GI and protein were observed in glucose or insulin responses, respectively. The four meals had no differential effect on observed energy intake or self-reported hunger, satiety, and prospective energy intake. Low GI meals produced the smallest postprandial increases in glucose and insulin. There were no effects for GI, protein, or their interaction on appetite or energy intake 4 h after breakfast.

Despite efforts to achieve a desirable weight, two-thirds of the population has an elevated body weight. Medications are useful in supporting weight loss, but produce adverse effects. This study compared the effects of amphetamine and modafinil on food intake and cardiovascular activity in healthy men and women. Participants (n = 11) completed 11 sessions. In random order, participants received placebo on five separate sessions and single oral doses of modafinil (1.75, 3.5, or 7.0 mg/kg) and amphetamine (0.035, 0.07, 0.14 mg/kg). Free time between hourly performance testing intervals gave participants the opportunity to eat. Like amphetamine, modafinil reduced the amount of food consumed and decreased energy intake, without altering the proportion of macronutrients consumed. Although both medications significantly increase heart rate and blood pressure at higher doses, the dose of modafinil that was efficacious in decreasing food intake did not significantly increase heart rate. Modafinil may be well suited for the treatment of obesity, although further studies with repeated dosing in overweight populations are warranted. Modafinil may have less adverse health consequences than some anorectic agents and greater treatment efficacy.