Establishing the Glycaemic Index of Fruit Drinks Using Different Measurement Methodologies

Study to Examine Glycaemic Responses to the Ingestion of Fruit Juices and Smoothies Using Different Measurement Methodologies.

Glycaemic responses to carbohydrates ingested as fruit sugars may vary depending on factors inherent to the fruit and the type of sugar. The aim of this project is to investigate the glycaemic responses to a range of commercially available fruit drinks and to establish the glycaemic index for each product relative to a glucose reference. Differences in recorded responses could also be influenced by the sample type (capillary blood vs interstitial fluid) and participant characteristics. Participants will ingest 8 test drinks including 5 different fruit drinks (OJ, AJ, S&B, ENERGISE, BLUE), each matched for carbohydrate to the glucose reference (CONTROL) which will be sampled two times, an additional sample of one of the smoothies (S&B) will also be replicated. Fingerstick capillary blood sampling alongside dual sited continuous glucose monitors (CGM) will measure glucose and lactate concentrations, subjective appetite sensations will also be recorded. The tests will follow best practice guidelines for glycaemic index testing. These data will provide insight into how differing formulations can alter the glycaemic responses to fruit drinks, and whether sampling technique can affect the interpretations of measurement.

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).