OBJECTIVE: Our objective was to determine the influence of the carbohydrate content of the diet preceding the oral glucose tolerance test (OGTT) in pregnancy on the test results and to evaluate the necessity of the recommended preparatory high-carbohydrate diet. STUDY DESIGN: Thirty-four women from our outpatient clinic were enrolled in this prospective study. After giving informed consent, each women underwent a 90-min lesson (supervised by a dietary assistant) covering the carbohydrate, protein and fat content of different foods. Women were then randomized and in a crossover design started a diet with either a low or a high carbohydrate content. We were aiming at a carbohydrate intake of 40% in the low-carbohydrate week (LCH) and 50% in the high-carbohydrate week (HCH). Compliance was monitored by a detailed food diary which the women kept and which included the weight of the foods they consumed. RESULTS: The actual dietary intakes as calculated from the food diaries showed that the mean caloric intake was 1801 +/- 314 kcal in the LCH and 2118 +/- 312 kcal in the HCH week (
