Among factors that affect diet-induced thermogenesis (DIT) are the sensory characteristics of food. The aim of this study was to test whether the sweet flavour obtained with a low-energy sweetener (aspartame) or with sucrose have a different effect on DIT. Following a standardized breakfast, 24 healthy male subjects were served three test lunches in a randomized fashion. Lunch contained soft white cheese added with maltodextrins and aspartame, or sucrose, or maltodextrins only (non-sweetened control) (each 900 kcal). Energy expenditure (indirect calorimetry) was monitored during the five postprandial hours. For the first two periods of measurement (30-60 and 90-120 min after meal ingestion), postprandial energy expenditure was significantly increased with sucrose compared to maltodextrins and maltodextrins plus aspartame, whereas no significant difference was found between maltodextrins and maltodextrins plus aspartame. No significant difference between lunches was observed for DIT expressed as incremental area above premeal baseline energy expenditure. Plasma glucose area under the curve was significantly lower for sucrose compared to maltodextrins plus aspartame. Plasma insulin area under the curve was significantly lower for sucrose compared to the other tests foods.
In conclusion: (1) variation in sweet-taste induced by aspartame or by sucrose does not seem to have a major effect on DIT in healthy humans; (2) differences in energy expenditure observed in the early postprandial period suggest a substrate effect.