OBJECTIVE -To evaluate in type 1 diabetic patients 1) the long-term feasibility of a highfiber (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/m 2 , 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 Ͻ 0.05) and number of hypoglycemic events (P Ͻ 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 Ͻ 0.001), HbA 1c (P Ͻ 0.05), and number of hypoglycemic events (P Ͻ 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.

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In the last 10 years nutritional research on diabetes has improved dramatically in terms of both number of studies produced and quality of methodologies employed. Therefore, it is now possible to attempt to provide the evidence on which nutritional recommendations for the prevention of type 2 diabetes could be based. We therefore performed a literature search and, among the papers published in indexed journals, we selected relevant epidemiological (mostly prospective) and controlled intervention studies. Lifestyle factors that have, so far, been consistently associated with increased risk of type 2 diabetes are overweight and physical inactivity. However, recent evidence from epidemiological studies has shown that the risk of type 2 diabetes is also associated with diet composition, particularly with: (1) low fibre intake; (2) a high trans fatty acid intake and a low unsaturated:saturated fat intake ratio; (3) absence of or excess alcohol consumption. All these factors are extremely common in Western populations and therefore the potential impact of any intervention on them is large: indeed, . 90 % of the general population has one or more of these risk factors. The ability to correct these behaviours in the population is estimated to reduce the incidence of diabetes by as much as 87 %. Recent intervention studies have shown that type 2 diabetes can be prevented by lifestyle changes aimed at body-weight reduction, increased physical activity and multiple changes in the composition of the diet. Within this context, the average amount of weight loss needed is not large, about 5 % initial weight, which is much less than the weight loss traditionally considered to be clinically significant for prevention of type 2 diabetes. In conclusion, new emphasis on prevention by multiple lifestyle modifications, including moderate changes in the composition of the habitual diet, might limit the dramatic increase in incidence of type 2 diabetes envisaged worldwide.

Childhood obesity is associated with an increased carotid intima-media thickness (IMT) and stiffness. Increased carotid wall thickening and rigidity are considered markers of subclinical atherosclerosis. The aim of the present study was to test the effect of two hypocaloric diets of varying glycemic index on weight loss and markers of subclinical atherosclerosis in obese children. Seventy consecutive obese children attending the Outpatient Weight Clinic of the Department of Pediatrics were invited to participate in an intensive dietary protocol. Twenty-six accepted and were randomly assigned to two different groups: the first group followed a hypocaloric low-glycemic index diet and the second a hypocaloric high-glycemic index diet. Anthropometric measures and biochemical tests were performed in all children. Quantitative B-mode ultrasound scans were used to measure intima-media thickness (IMT) and diameters of the common carotid artery. Considering both groups together, at 6 months, body mass index decreased from 28.3 +/- 3.1 to 25.8 +/- 3.3 kg/m(2), systolic blood pressure from 119 +/- 12 to 110 +/- 11 mmHg (P< 0.001), diastolic blood pressure from 78 +/- 8 to 74 +/- 7 mmHg (P< 0.001), IMT from 0.48 +/- 0.05 to 0.43 +/- 0.07 mm (P< 0.001), stiffness from 3.57 +/- 1.04 to 2.98 +/- 0.94 mm (P = 0.002), and high-sensitivity C-reactive protein from 1.5 +/- 0.9 (values log transformed) to 0.4 +/- 1.1 (P < 0.001). No differences were detectable in fasting serum triglycerides, total cholesterol, and high-density lipoprotein cholesterol. Insulin resistance (calculated by the HOmeostatic Model Assessment index [HOMA] score) significantly reduced only in the low-glycemic-index diet group (P < 0.04). In conclusion, this study confirms a benefit of hypocaloric diets on carotid IMT and stiffness in obese children and demonstrates, for the first time, an amelioration of insulin sensitivity in obese children after a low-glycemic index diet. These results justify the advice to obese children to follow a low-glycemic index diet in order to improve their cardiometabolic profile.

OBJECTIVE:To investigate the possible associations between sleep apnea syndrome, hyperinsulinemia=insulin resistance and hyperleptinemia in subjects with different degrees of body mass index. DESIGN: To test for the presence or absence of sleep apnea syndrome in association with hyperinsulinemia=insulin resistance and hyperleptinemia. SUBJECTS: Twenty subjects with different body mass index (mean BMI 30.9 AE 4.2). MEASUREMENTS: Insulin action and plasma soluble leptin receptor were measured by euglycemic hyperinsulinemic glucose clamp and by ELISA method, respectively. Occurrence of sleep apnea syndrome was assessed by clinical and nocturnal monitoring using a validated sleep apnea recorder. RESULTS: The apnea=hypopnea index (AHI) was positively correlated with plasma soluble leptin receptor (0.76; P < 0.001) and negatively with the degree of insulin-mediated glucose uptake (r ¼ 7 0.73; P < 0.001). In a multivariate analysis AHI was associated with plasma soluble leptin receptor and insulin mediated glucose uptake independently of age, gender, BMI, plasma leptin levels and PaCO 2 . CONCLUSION: Sleep apnea syndrome is associated with plasma soluble leptin receptor and insulin resistance independently of BMI.

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Our data show that meals with the same carbohydrate content but a different glycaemic index produce clinically significant differences in postprandial blood glucose.

The effects of the high-carbohydrate diet on blood glucose control in NIDDM patients differ according to severity of glucose intolerance.