Glucose, Insulin and Metabolic Response to Soy and Whey Protein among Normal Healthy Weight Indians

INTRODUCTION High quality dietary protein intake has been linked to the healthy growth and development of lean tissue. Both milk and legumes are recognized as high quality protein sources. However, the acute effect of consumption of different sources and amounts of high quality protein on glucose homeostasis, particularly in South Asian Indians, is unknown. This is relevant in this population group, which has a greater risk of developing diabetes, and a habitually low intake of high quality protein. METHODS This study investigated the effect of milk (whey) and legume‐based (soy) protein on glucose homeostasis and energy metabolism, among healthy normal weight Indians. The study tested protein type (soy protein vs. whey protein) and dose (15% vs. 30% Energy). Healthy adult males between ages of 20–35 years (n=15) received four test meals in random order. Blood samples were collected at the following time points Basal (−10 and −5 min), and post meal (15, 30, 45, 60, 90, 120,180, 240 and 300 min) for glucose and insulin estimations. The incremental area under the curve was measured for plasma glucose and insulin. Energy expenditure and substrate oxidation were measured every 30 minutes for 300 minutes after the meal. Satiety was estimated using visual analogue scale at 0, 10, 40 min, and every half hour thereafter. RESULTS The incremental area under the curve for plasma insulin was significantly higher for 30% whey compared to 30% soy protein (p<0.01). There was no difference in the insulinogenic response between 15% whey and 15% soy protein (p=0.07). Within a specific protein, only whey protein demonstrated a higher insulin response with a higher dose (p<0.01). There were no differences in plasma glucose across protein source or doses. Satiety and energy expenditure did not differ between protein source and doses. CONCLUSION At lower doses, whey and soy protein do not elicit different insulinogenic responses. However, at higher doses whey protein has greater insulinogenic response compared to soy protein, making soy protein a better source for those at greater risk for developing diabetes. Support or Funding Information DuPont Nutrition & Health