After eating a meal, nutrients are absorbed into the bloodstream triggering the secretion of hormones involved in nutrient metabolism. Insulin typically always rises in response during this absorptive phase of digestion. However, a protein rich meal, also causes a rise in glucagon levels, a hormone that we normally associate as being the antagonist of insulin. Explain why a high protein meal might increase both insulin and glucagon levels while a high carbohydrate meal only increases carbohydrate levels.