A diet in line with RDAs is seldom achieved by IDDM patients. High post-prandial glucose levels are often attributed to food excess rather than to inadequate insulin doses. Lower dietary CHO with greater fat (in particular SFA) and protein are progressively scheduled instead of increasing insulin units. We studied 194 IDDM patients (1-23 yr) on a diet conforming to RDAs with a restriction of sucrose and without a quantitative approach and exchange lists of food for one year. The diet consisted of a high intake of starchy foods and vegetables and a restricted amount of animal products. HbA1c mean values of the year were used as an indicator of metabolic control. The mean daily insulin dose was 0.53 U/kg in patients with diabetes duration (DD) < 2 yr and 0.81 U/kg in those with DD > 2 yr. Mean annual HbA1c was 7.1 +/- 0.9%. The prevalence of obesity was low (5.7%). Adolescent females were more obese than males. A dietary approach in line with RDA requirements, that may help prevent any complications related to an inappropriate diet pattern, coupled with a dynamic insulin adjustment, is the first-line intervention to prevent complications in IDDM patients.