The effects of a high-carbohydrate, high-protein or balanced lunch upon later food intake and hunger ratings.

This study compared the satiating properties of three liquid lunches (450 kcal each), one dominant in protein (71.5% of energy), a second in carbohydrates (99% of energy) and a third containing an equal mixture of the first two formulations, in a within-subjects, repeated measures design. At an ad libitum dinner meal, 12 women consumed 31% more kilocalories in the high-carbohydrate lunch condition than in the high-protein lunch condition and 20% more kilocalories than in the mixture lunch condition. Similar results emerged for the amounts of protein and fat ingested at dinner. Subjects also reported significantly greater pre-dinner hunger and excitement about eating in the carbohydrate lunch condition than in the protein lunch condition. Greater enjoyment of dinner was also found after the carbohydrate lunch than after the mixture and protein lunches.