| heal.abstract |
Background: When substituted for carbohydrate in a meal, dietary protein enhances glycaemic control in subjects with type 2 diabetes (DM2). It is unknown whether the effect is a result of increased protein or reduced carbohydrate. The present study aimed to compare the effects of two meals differing in protein to fat ratios on post-prandial glucose and insulin responses. Methods: This was a crossover, blind study in which obese subjects with (n = 23) and without (n = 26) DM2 consumed two meals in random order with equal amounts of energy (3.1 MJ, 741 kcal), fibre and carbohydrates and a 1-week washout period. Meals were a high protein, low fat (30% protein, 51% carbohydrates, 19% fat) meal and a low protein, high fat (15% protein, 51% carbohydrates, 34% fat) meal. Subjects were matched for age and body mass index. Plasma glucose and insulin were measured at fasting, 30, 60, 90, 120 min post-prandially. Insulin resistance and insulin sensitivity were assessed. Results: There was no significant meal effect on glucose and insulin responses within groups. Glucose response was higher in diabetic (120 min 11 ± 0.7 mmol L -1) compared to nondiabetic (120 min 5 ± 0.2; P < 0.001) subjects. Diabetic subjects had significantly higher insulin resistance (P < 0.001) and lower insulin sensitivity (P < 0.001) than nondiabetics. Although peak insulin levels, 60 min post-prandially, did not differ between groups (81 ± 9 pmol L -1 for diabetic versus 79 ± 7 pmol L -1 for nondiabetic subjects), they were achieved much later, 90 min post-prandially, in diabetic, (99 ± 8 pmol L -1) compared to nondiabetic (63 ± 7 pmol L -1, P = 0.002) subjects. Conclusions: Manipulating protein to fat ratio in meals does not affect post-prandial plasma blood glucose or insulin responses in obese people with and without DM2. © 2010 The Authors. Journal compilation © 2010 The British Dietetic Association Ltd. |
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