Does a meal containing green tea extract lower diabetes risk?

The study will investigate the effect of 6g of a green tea extract (high in polyphenols) cooked into a meal containing 50 g of available carbohydrates in the form of jasmine rice vs placebo (no green tea) in the morning and at night. The intervention will be run by University research students overseen by Senior University researchers. Blood glucose will be measured at baseline, 15, 30, 45, 60, 90, 120, 150 and 180 minutes to assess the postprandial glucose response. Insulin will be measured at baseline and at 30, 60, 90, 120, 150 and 180 minutes post meal to assess postprandial insulin response. Participants will also complete questionnaires relating to their habitual diet and physical activity. This is a 4 way crossover with participants completing the test (polyphenol) and placebo meals in the morning and also in the evening. Morning session Participants will be provided with a standardised commercially available frozen meal to consume between 7 - 9 pm the night before each testing day, then will be asked to fast until testing is complete, drinking only water. Participants are also asked to avoid foods high in polyphenols and strenuous exercise for 24 hours prior to testing. Participants will be asked to come in to the lab at 7 am in the morning following an overnight fast. They will have an initial finger prick tests done to provide fasting levels of blood glucose and insulin then be given either a test meal or placebo meal containing 50 g of available carbohydrates from white rice, which must be consumed within 15 minutes. Evening session The same protocol as for the mornings will be carried out for evening testing, but with participants consuming a standardised commercially available frozen meal between 8 and 9 am and arriving at the testing facility at 6 pm after fasting throughout the day. Participants will consume the test doses and placebo in a cross-over fashion (four sessions in total) with at least three days washout in between each treatment. All treatment will be administered and supervised on site. Prior to each study session participants will be asked to confirm that they have fasted (either overnight or during the day depending on the session) and consumed the control meal provided.