We propose that the GI response to feeding varies inversely with body weight. This hypothesis predicts that as body weight increases, the response to a given meal decreases in terms of motility, neurohormonal feedback, sensation and satiety. This provides an attractive explanation for why thin individuals stop eating after a small amount of food (i.e. limited gastric relaxation, rapid gastric emptying, powerful nutrient feedback with early satiety)and, conversely, why obese patients continue to eat even after nutritional requirements have been met (i.e. large gastric relaxation, slow gastric emptying, weak nutrient feedback with delayed satiety).