Which statement best describes the relationship between obesity and incretin effect in glucose regulation?

• A. Obesity is associated with reduced incretin effect and increased insulin resistance.
• B. Obesity increases incretin effect, improving insulin sensitivity.
• C. Incretin effect is unaffected by body weight.
• D. Obesity reduces insulin production only.

Answer: (A)

The key idea is how gut hormones that boost insulin after a meal—called the incretin effect—are altered in obesity. Normally, hormones like GLP-1 and GIP increase insulin secretion when you swallow glucose, so the insulin response to oral glucose is greater than to the same amount of glucose given intravenously. In obesity, this incretin effect is blunted, meaning the meal-stimulated insulin release isn’t as strong as it should be. At the same time, obesity often brings insulin resistance, so tissues respond less to insulin and the body needs more insulin to achieve the same glucose control. Put together, obesity is linked to a reduced incretin effect and increased insulin resistance, which explains why that statement fits best. The other ideas don’t align with this pattern: the incretin effect isn’t increased by obesity, isn’t unchanged across body weight, and obesity involves changes in insulin dynamics beyond just production.