The beneficial effect of a diet with low glycaemic index on 24h glucose profiles in healthy young people as assessed by continuous glucose monitoring

Elevated postprandial glycaemia has been linked to CVD in a number of different epidemiological studies involving predominantly nondiabetic volunteers. The MiniMed continuous glucose monitor, which measures blood glucose every 5 min, over a 24 h period, was used to investigate changes in blood glucose readings before and after instigating a diet with low glycaemic index ( GI) for 1 week in free-living healthy individuals. Nine healthy people ( age 27 ( SEM 1.3) years, BMI 23.7 ( SEM 0.7) kg/m(2), one male, eight females) completed the study. A reduction in GI ( 59.7 ( SEM 2) v. 52.1 ( SEM 2), P < 0.01) occurred in all nine subjects while energy and other macronutrients remained constant. A significant reduction was also observed in fasting glucose at 06.00 hours ( 5.4 ( SEM 0.2) v. 4.4 ( SEM 0.3) mmol/l, P < 0.001), mean glucose ( 5.6 ( SEM 0.2) v. 5.1 ( SEM 0.2) mmol/l, P = 0.004), area under the 24 h glucose curve ( 8102 ( SEM 243) v. 750 ( SEM 235) mmol/l per min, P = 0.004) and area under the overnight, 8 h glucose curve ( 2677 ( SEM 92) v. 2223 ( SEM 121) mmol/l per min, P = 0.01). The present study provides important data on how a simple adjustment to the diet can improve glucose profiles that, if sustained in the long term, would be predicted from epidemiological studies to have a favourable influence on CVD.