A randomized behavioural trial targeting glycaemic index improves dietary, weight and metabolic outcomes in patients with type 2 diabetes

Abstract

AbstractObjectiveGlycaemic index (GI) reflects the postprandial glucose response of carbohydrate-containing foods. A diet with lower GI may improve glycaemic control in people with diabetes. The purpose of the present study was to evaluate the change in outcomes following a behavioural intervention which promoted lower-GI foods among adults with diabetes.DesignA pre-test–post-test control group design was used with participants randomly assigned to an immediate (experimental) or delayed (control) treatment group. The intervention included a 9-week, group-based intervention about carbohydrate and the glycaemic index. Dietary, anthropometric and metabolic measures were obtained pre/post-intervention in both groups and at 18-week follow-up for the immediate group.SettingThe study was conducted in a rural community in the north-eastern USA.SubjectsAdults having type 2 diabetes mellitus for ≥1 year, aged 40–70 years and not requiring insulin therapy (n 109) were recruited.ResultsFollowing the intervention, mean dietary GI (P < 0·001), percentage of energy from total fat (P < 0·01) and total dietary fibre (P < 0·01) improved in the immediate compared with the delayed group. Mean BMI (P < 0·0001), fasting plasma glucose (P = 0·03), postprandial glucose (P = 0·02), fructosamine (P = 0·02) and insulin sensitivity factor (P = 0·04) also improved in the immediate group compared with the delayed group. Mean waist circumference among males (P < 0·01) and body weight among males and females (P < 0·01) were significantly different between treatment groups.ConclusionsEducating clients about carbohydrate and the glycaemic index can improve dietary intake and health outcomes among adults with type 2 diabetes.