Clinical Research Directory

Glycaemic Responses to Carbohydrate-rich Meals (GlyCarb)

Carbohydrate-rich foods such as potatoes, bread, rice, pasta, breakfast cereals, biscuits and other snacks are a major component of the human diet. The effect of different carbohydrate-rich foods on blood sugar (glucose) levels after a meal varies between foods. This is relevant to health because studies have shown that regular intake of carbohydrate foods that cause large increases in blood glucose levels after ingestion can be detrimental to metabolic health. The aim of the GlyCarb study is to investigate how food structure influences postprandial glycaemic responses to carbohydrate foods. This will be achieved through a series of acute postprandial studies (up to 5 studies), wherein healthy participants within each postprandial study consume a pair of carbohydrate-rich test meals while wearing a continuous glucose monitoring system (CGM). Each postprandial study will use the same GlyCarb Remote standard protocol, where a randomised cross-over design is used to measure the glycaemic response to two carbohydrate-rich test meals, one "test" and one "control". Both meals will be matched by carbohydrate content, contain similar ingredients and have a similar physical appearance, but will differ in one key food property (e.g., altered food structure) to test its effect on postprandial glycaemia. In each postprandial study, habitual dietary intake and body composition will be captured at baseline as part of the participant characterisation. Participants will consume two different carbohydrate-rich test meals twice, on separate occasions, in a randomly allocated order over a 10 to 14-day period of continuous glucose monitoring. Data from the continuous glucose monitors will be used to assess the postprandial glycaemic response to each carbohydrate food. The participants will be required to complete brief questionnaires designed to evaluate differences in palatability (taste, texture, portion size) and satiety amongst test meals. Study participant feedback will be requested at the end of the study and used to assess and improve future study procedures. The GlyCarb study will enable new understanding of how food properties influence glycaemic responses to different types of carbohydrate foods. Ultimately, the findings will inform the rational design or reformulation of food products and diets to support a healthy glucose metabolism.

The Effect of Hydration on Postprandial Metabolic Responses

Certain populations, such as industrial workers and endurance athletes are particularly susceptible to dehydration due to exposure to heat for long periods of time causing evaporative water loss via sweating. The physical and cognitive decrements associated with dehydration have been widely researched, however the effect of dehydration on metabolism is lesser known. As climate change is causing temperatures to rise, and metabolic diseases such as type 2 diabetes are more common, the effect of dehydration on metabolism, specifically glycemic response to meals, needs to be established for future recommendations in clinical, environmental and athletic settings. Therefore, the aim of this study is to investigate the effect of acute exercise-induced dehydration on subsequent metabolic responses to feeding (i.e. glycaemia and insulinaemia).