Scientific Study

OBJECTIVE: Glycaemic 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. DESIGN: A 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. SETTING: The study was conducted in a rural community in the north-eastern USA. SUBJECTS: Adults having type 2 diabetes mellitus for > or =1 year; aged 40-70 years and not requiring insulin therapy (n 109) were recruited. RESULTS: Following the intervention; mean dietary GI (P < 0.001); percentage of energy from total fat (P < 0.01) and total dietary fiber (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. CONCLUSIONS: Educating clients about carbohydrate and the glycaemic index can improve dietary intake and health outcomes among adults with type 2 diabetes.