Effect of volume and type of beverage consumed with a standard test meal on postprandial blood glucose responses

To study the effect of volume and type of beverage consumed with a meal on blood glucose (BG) responses, 12 normal subjects ate a standard test meal, Diabetes Screening Product (DSP), with 50, 250, 500, 750 or 1000ml water, or 250ml coffee or tea on separate days after overnight fasts. Water volumes were tested twice, making 12 tests done by each subject in a randomized block design. Finger-prick blood was taken before and 15, 30, 45, 60, 90 and 120min after starting to eat. The mean and variation of BG responses were compared by 2-way ANOVA. Mean BG 15min after DSP plus 500ml water was 0.6mmol/L greater than after DSP plus 50ml water (p<0.05). At 30min, BG was 0.5-0.7mmoTn greater after 500 and 750ml water than 50, 250, and 1000ml(p<0.005). At 90min, BG was 0.3mmol/L greater after 50 and 250ml water than after 500 and 750ml (p<0.005). At 120min, BG was 0.5mmol/L greater after 50ml than 500 and 750ml (p<0.001). Coffee and tea resulted in greater 45min BG than the same volume of water (p<0.005), while BG 60min after coffee was greater than after both tea and water(p<0.05). Volume and type of beverage did not significantly affect the incremental area under the curve or the variability of BG. We conclude that, in normal subjects, the volume and type of beverage consumed with a test meal influences the pattern of blood glucose response but has no effect on the incremental area under the glycaemic response curve. Since the volume, but not- the type of beverage, affected the blood glucose concentration 2h after eating a standardized meal volume should be used when testing an individual's carbohydrate tolerance status. (C) 1998 Elsevier Science.