Gender differences in fat preference and perception in healthy volunteers.

Participants will be exposed to four different taste sessions. The first two session will involve fat taste sensitivity tests (on paper and in milk in randomised order) and the last two involve preference for salt/fat combinations and preference for sugar/fat concentrations (in randomised order). The oral fat taste sensitivity tests will be assessed by using a three ascending forced choice tests. Participants will be asked to identify the "odd" tasting sample from three samples (two controls and one fat containing sample), in ascending concentration of fat, in which the lowest detectable fatty acid concentration will be identified. The detection threshold was defined as the concentration that was correctly identified as the odd sample three consecutive times. The total number of tests carried out will depend on the ability to taste fat. This will be done by using milk as base (one session) or filter paper (one session). In the filter paper session, the fatty acid concentrations or control (mineral oil) is loaded onto filter paper placed on participants tongue. The following concentrations of oleic acid (C18:1) are used in the fat taste sensitivity test: 0.02, 0.06., 1, 1.4, 2, 2.8, 3.8, 5, 6.4, 8, 9.8, 12, 20 mM. Participants will taste food samples with different salt and fat concentrations (tomato soup) and different sugar and fat concentrations (custard). Food samples will be 15 ml. There will be 16 salt/fat combinations and 16 sugar/fat combinations. Salt concentrations are 0, 0.35, 0.7 and 1.5% salt. Sugar concentrations are 0, 5, 10 and 20%. Fat concentrations are 0. 5, 10 and 20%. The duration of the sessions will be between 30 - 90 minutes, with at least two days in between the sessions.