Recent evidence shows that dietary supplementation with resistant starch (RS) increases fat catabolism and resting energy expenditure and decreases plasma insulin and glucose responses as well as the gut-derived hormone, glucose-dependent insulinotropic polypeptide (GIP). Consumption of whey protein has also been shown to increase energy expenditure and favorably affect gut hormones. Thus, investigators tested consumption of both RS and whey protein on energy expenditure and gut hormones in lean and obese women and men.

Consumed separately, resistant starch (RS) and whey protein (WP) favorably affect energy metabolism and gut hormones, as well as suppress feelings of hunger. These findings are important because release of certain gut hormones (i.e., GIP) is associated with a lower resting energy expenditure (REE) in healthy humans. Interestingly, a recent study showed that ingestion of RS reduces postprandial GIP and increases postprandial REE and fat utilization in healthy men and therefore may be an effective strategy in weight management. Thus, there is a need to replicate these findings in a healthy cohort of lean and obese women and men.

The purpose of this study was to examine the effects of RS on the number of calories burned after eating a meal, as well as specific hormones that are released from the stomach and intestines following meal ingestion in healthy lean and obese women and men. Investigators used a single ingestion of a meal supplemented with or without the resistant starch and whey protein.

Inclusion Criteria:

• overweight or lean but otherwise healthy

Exclusion Criteria:

• Participants will be excluded if they smoke; have experienced excessive weight loss/gain of > ±2kg in the previous 2 months; are currently taking medications for cardiovascular or metabolic disease.