The effects of fruit and vegetables in conjunction with low-energy diet as adjuncts to a prudent diet were compared for 6 months in a randomized, single blind trial in the management of 202 group A and 204 group B patients with acute myocardial infarction. Dietary intakes were obtained based on weighing of fruit, vegetable and legume intake and weekly diet diaries. After 6 months of follow-up, mean body weight, waist/hip ratio and glucose intolerance fell significantly in patients in group A compared with those in group B. Body weight declined by 5.3 kg in group A versus 2.2 kg in group B (95% confidence interval of difference (CI) 1.28-4.92), waist/hip ratio decreased by 0.05 in group A and 0.02 in group B (95% CI 0.01-0.10), and glucose intolerance decreased by 0.85 mmol/l in group A versus 0.19 mmol/l in group B (95% CI 0.19-1.21). There was a significant net decrease in serum triglycerides (0.18 mmol/l), systolic and diastolic blood pressures (7.9/4.7 mmHg), and a net increase in high-density lipoprotein cholesterol (0.10 mmol/l). Underlying these changes, group A patients had 393 g/day net increase in the consumption of fruit and vegetables and 1,160 kJ/day net decrease in energy intake compared to these changes in groups. Those who made greater changes in diet also had greater improvements in central obesity, glucose intolerance and in other associated disturbances.