The Effect of a Low Glycaemic Index Breakfast on Blood Glucose, Insulin, Lipid Profiles, Blood Pressure, Body Weight, Body Composition and Satiety in Obese and Overweight Individuals: A Pilot Study

Background: Low glycaemic index (GI) carbohydrates have been shown to have favourable effects on blood glucose, lipid profiles and satiety in individuals with chronic disease. However, modifying GI for the entire diet may be too complicated for an average individual without professional support. This study aims to investigate the health benefits of changing the GI index of a single meal a day, a more achievable goal. Objective: The objective of this study was to investigate whether altering the GI of one meal/day (breakfast meal only) for 21 days in obese individuals would have a favourable effect on fasting serum glucose, low density lipoproteins, high density lipoproteins, insulin and triglycerides. Design: A randomised, crossover design was used to compare the effects of a high GI with a low GI breakfast replacement meal. The macronutrient compositions of the breakfasts were matched. The subjects, 16 women and 5 men, who were overweight or obese, were randomly allocated to two intervention periods of 21 days each separated by a washout interval of 21 days. Subjects were seen at the beginning (baseline) and end of each intervention period (final). Results: The change in fasting glucose (baseline versus final data) during the Low GI period was significantly lower (p < 0.05) from that during the High GI period). Fasting triglycerides, insulin and fasting total, HDL LDL cholesterol were unaffected by the daily changes in the type of breakfast. The change in satiety ratings before lunch (baseline versus final) during the Low GI period was slightly higher from that during the High GI period. Conclusion: Results of this study show beneficial changes in fasting glucose and satiety by modifying the GI of a single meal per day, suggesting such modifications could potentially be a useful public health recommendation.