Establishing the Glycaemic Index of Vegetable Smoothies

Glycaemic responses to carbohydrates ingested as fruit and vegetables may vary depending on factors inherent to the fruit or vegetable, and on the type of sugar. The aim of this project is to investigate the glycaemic responses to two new fruit and vegetable smoothies, and to establish the glycaemic index for each product relative to a glucose reference. Participants will undertake 4 postprandial tests with 2 different test drinks following best practice guidelines for glycaemic index testing. The test drinks (GREEN and RED) will be matched for carbohydrate to the glucose reference (CONTROL) which will be sampled two times. Fingerstick capillary blood sampling will measure glucose concentrations. These data will provide insight into how differing formulations can alter the glycaemic responses to fruit and vegetable drinks.

Inclusion Criteria: * Age: 18-65 years * Body mass index 18-30 kg/m2 Exclusion Criteria: * diagnosis of any form of diabetes * intolerances or allergies to any of the study procedures (e.g. fructose/inulin intolerance) * Fructose malabsorption * Inborn errors of fructose metabolism (e.g. fructokinase deficiency, aldolase B deficiency, fructose-1,6-bisphosphatase deficiency) * pregnant or lactating * any condition that could introduce bias to the study (e.g. diagnoses of lipid disorders, including cardiovascular disease, or therapies that alter lipid or glucose metabolism, such as statins or niacin).