Genomics of sweet and fat taste in the prevention of obesity.

Observational study which will evaluate participants dietary intake, weight status and taste sensitivity (taste detection threshold, supra-intensity rating and preference testing). This data will be compared with allelic variation and expression of genes involved in taste from tissue collected from blood and the oral cavity. Participants will be required for a minimum of 4 testing session, which will take place over a one month period, and each testing session will be seperated by at least 24 hours. Visit 1 will provide participants with information about the study, body measurments will be completed (weight, height, waist circumference and papillae density) and blood will be drawn (participants will attend after an overnight fast) - total time for visit 1 will be 1.5 hours. Visit 2 and 3 will collect the same data with each visit being 2.5 hours each. Participants will first provide oral samples though a non-invasive scraping technique, followed by tasting of sensory samples to determine individual sweet and fat taste measures (taste detection threshold, supra intensity ratings and preference testing). Particiapants will attend visits 2 and 3 after a 2 hour fast. During visit 4, 4-6 tastebuds will be collected from the anterior of the tongue by a medical practitioner after a 2 hour fast - total time of visit 1 hour. Additionally, a subset of particpants (n=10 - half lean half obese) will be required for a single visit (4 hours) to assess breath volatiles after the consumption of an lipid emulsion beverage. Participants will be tested after a overnight fast, and breath volatiles measured every 30-45min.