The influence of oral taste sensitivity on satiety and nutrients intake in human subjects

Subjects will be screened based on their taste sensitivity to sucrose and MSG before they participate into the soup preload and eating behavior study.. The study will be conducted over 3 non-consecutive test days with one-week interval at the sensory laboratory at the University of Queensland.Three different soups will be tested: 1- control soup: 12g plain flour + 200ml water; 2-MSG soup: 12g plain flour + 1g MSG + 200ml water; 3-sweet soup: 9.6g plain flour + 2g sucrose + 200ml water; Participants will arrive at 8:00 - 8:30 a.m. in a fasted state having consumed nothing but water from at least 2300 hours the night before. After brief introduction and the first saliva collection, they will be provided with 200ml of either MSG soup, placebo soup or Sweet soup in randomised order 10 min after arrival. The washout time between two soup conditions was one-week. They will be asked to finish the soup within 5 minutes using a given spoon. Subjects will then stay in the lab for 60 minutes before the buffet meal was provided. They will choose any kinds of food and consume as much or as little as they want until reach comfortably fullness and satiation. Participants are free to ask for more foods if they finish any of the food served. The ad libitum meal session will last for up to 40 minutes.. Subjects will also taste 5ml samples of MSG and sweet soup before preload, then at 0 minute and 60 minutes after the soup preload. Soup pleasantness was measured by rating on a visual analogue scale after tasting the sample. Subjective appetite and sensory specific appetite will be measured using visual analogue scales. Saliva samples will be taken at the following time points: arrival, 0min, 30 min 60 min after the soup and after the ad libitum meal.