Long-term dietary treatment with increased amounts of fiber-rich low-glycemic index natural foods improves blood glucose control and reduces the number of hypoglycemic events in type 1 diabetic patients.

OBJECTIVE To evaluate in type 1 diabetic patients 1) the long-term feasibility of a high-fiber (HF) diet composed exclusively of natural foodstuffs and 2) the efficacy of this diet in relation to blood glucose control and incidence of hypoglycemic episodes. RESEARCH DESIGN AND METHODS The study was randomized with parallel groups. Participants were part of a larger multicenter study on the effects of acarbose on glucose control in diabetes. A total of 63 type 1 diabetic patients, age 28 +/- 9 years, BMI 24 +/- 0.6 kg/m2, after a 4-week run-in period on their habitual diet, were randomized to either an HF (n = 32) or a low-fiber (LF) diet (n = 31) for 24 weeks. The two diets, composed exclusively of natural foodstuffs, were weight-maintaining and, aside from their fiber content, were similar for all nutrients. At the end of the run-in period and the dietary treatment, fasting blood samples for the measurement of plasma cholesterol, HDL cholesterol, triglyceride, and HbA(1c) were collected. A daily glycemic profile was performed on a day in which the participants had consumed a standard menu representative of their treatment diet (HF or LF). RESULTS Of the 63 study subjects, 29 in the HF group (91%) and 25 in the LF group (81%) completed the study Compared with the LF diet, the HF diet after 24 weeks decreased both mean daily blood glucose concentrations (P < 0.05) and number of hypoglycemic events (P < 0.01). When compliance to diet was taken into account, 83% of the subjects on the HF diet and 88% on the LF diet were compliant. In this subgroup, compared with the LF diet, the HF diet significantly reduced mean daily blood glucose concentrations (P < 0.001), HbA(1c) (P < 0.05), and number of hypoglycemic events (P < 0.01). CONCLUSIONS In type 1 diabetic patients, an HF diet is feasible in the long term and, compared with an LF diet, improves glycemic control and reduces the number of hypoglycemic events.