The effect of a high protein preload drink on satiety, food intake, satiety-related hormones and protein metabolites.

Each participant participated in 3 sessions in total with a minimum of 2 days between each session. Two flavoured milk-based preload drinks differing in carbohydrate and protein were administered 120 min before an ad libitum test meal. A water control was also administered. Each subject was provided with a standardised breakfast to consume 3 h before coming to the laboratory and only water is permitted thereafter. Upon arrival at the laboratory, a cannula was placed into a vein in the subject's arm for repeated blood draws. Subject was given a preload drink to consume within 5 min. Subjects completed some questionnaires to assess their feelings of appetite and had 8 blood samples (10 ml each) collected within 120 min. At the end of the 120 min, the cannula was removed and subjects were provided with a hot meal and water to consume until satisfied within 15 min. The time involvement for each subject on each session day was at least 170 min and there are 3 sessions, therefore 510 min. The 300 ml preload drinks used a sweet flavoured milky solution as a base to which 45 g of either maltodextrin, a carbohydrate with a simple structure or cheese whey protein isolate will be added. All the ingredients in the preload drinks are natural food-grade materials normally consumed in foods. The amount of carbohydrate and protein in 300 ml of the carbohydrate-enriched preload drink was 72 g and 3 g, respectively. The whey protein-enriched preload drink contributed 26 g carbohydrate and 46 g protein per 300 ml drink.