Effects of Co-ingesting a Low/High GI Meal With Different Fat Saturation on Postprandial Glucose, Insulin, and Triacylglycerol Responses in Healthy Participants

Overview

It is now recognized that diet plays a critical role in the etiology and management of the chronic diseases such as diabetes, obesity and cardiovascular disease. A high consumption of fat, especially saturated fat, is an established risk factor for Cardiovascular Disease.The glycaemic index (GI) is a measurement of the ability of different types of carbohydrate-based foods to raise blood glucose. The interest in low GI food as a weight management tool has been increasing. Different types of carbohydrates differ in their ability to increase postprandial blood glucose and insulin secretion, and may also modulate the effect of different fatty acids. The current study will compare the consumption of low and high GI carbohydrate with different fat saturation on postprandial glucose, insulin, and triacylglycerol responses in healthy participants. The data generated will have direct applications in public health policy and clinical nutrition management of chronic disease. The outcomes of the study will significantly contribute to the long term national goals of Singapore to manage and to reduce the incidence of chronic disease associated with the metabolic syndrome.

This study will be conducted using a randomized, crossover design with six dietary phases: a low GI meal or a high GI meal with saturated fat, monounsaturated fat or polyunsaturated fat. All participants will be randomly allocated to the six test meals, with the order balanced. Fifteen participants aged between 21 and 40 years will be recruited from the general public in Singapore. During the testing session, a maximum of eleven blood samples will be collected by fingerpricks and cannulation. Fingerpricks and cannulation may cause minor discomfort and there may be some slight bruising around the site. Fingerpricks and cannulation will be done by an experienced research nurse or a trained research officer to minimize participant discomfort. If bruising does occur, it should disappear within one day and it should not affect participants' regular daily activity. Participants will be limited to a maximum of two tests per week. In addition, blood collection will be carried out in a sterile designated area and thus the risk of infection will be very low. On rare occasions, participants may feel unwell during or after the testing session. The investigators have several metabolic suites with beds for these individuals to rest on. The research nurse and research officers will monitor the individuals' condition and they will be provided with a ride home if required. All the study foods will be prepared in a hygienic manner in a purpose-built research kitchen maintained to the highest hygiene standards. The research staff has undergone basic training in food hygiene procedures. Hence, the risk of infective acute gastroenteritis will be minimal. A number of dietary interventions have aimed to investigate the effect of dietary fat quality on glucose, insulin and lipidemia response. Up to now there have been few studies connect the glycaemic load and fat quality together. The investigators study's results will help public choose fat quality and carbohydrate quality in the diet. Participants will be provided with some snacks at the end of each testing session. In addition, participants will be provided with their blood glucose, blood insulin, blood lipid profile, blood pressure, and body composition results, with a brief interpretation of these at the conclusion of the study.