Apple versus chocolate: Evidence for discrimination of distension-related and calorie-related satiety signals in post-prandial fullness and hunger, and in the quality and location of other body sensations

Gastric distension and detection of macronutrients (calories) in the gut are determinants of satiation and satiety. We tested effects of these variables on body sensations after eating, and their connection with visual-analogue scale (VAS) hunger and fullness ratings. Participants completed VAS ratings and quality and location of body sensations tasks after consumption of milk chocolate (38 g, 200 kcal) versus fresh apple fruit matched for weight (38 g, 20 kcal) and matched for calories (380 g, 200 kcal). Effects of food weight (380 vs 38 g) were large and located predominantly in the abdominal region. They also occupied a greater body area and occurred sooner after eating than effects related to calories (200 vs 20 kcal). The same pattern was apparent in the results from the quality of sensations task. VAS ratings indicated that hunger was affected by food volume and calories, whereas fullness was affected primarily by food volume. Together, these results provide evidence of dissociation of the perceived after-effects of food ingestion related to food volume and food calorie content in humans. Additionally, the studies demonstrate the utility of two rarely used, semi-quantitative tasks, which generate information on the identity, intensity, valence, and location of eating-related sensations.