Effect of fasting in Ramadan on body composition and nutritional intake: a prospective study.

BACKGROUND: The present study aimed to assess the effects of Ramadan intermittent fasting on body weight and composition and the effects of age and sex. METHODS: Body weight, height, waist and hip circumferences were measured, body mass index (BMI) was calculated and fat mass, fat-free mass and percentage body fat were assessed by bioelectrical impedance on 240 adult subjects (male: 158) who fasted between sunrise and sunset for at least 20 days. Measurements were taken 1 week before and 1 week after Ramadan. Energy and macronutrient intakes were assessed using a 3-day food frequency questionnaire on a sub-sample of subjects before and during Ramadan. RESULTS: Subjects were grouped according to age and sex: ≤35 years (n = 82, males: 31) and 36-70 years (n = 158, males: 127). There were significant reductions in weight and BMI (P < 0.001) in almost all subjects, with the biggest being in males ≤35 years [-2.2% (SE 2.2%), P < 0.001]. Waist and hip circumferences fell in most subjects, except females aged 36-70 years. Fat mass fell in most subjects, ranging from 2.3% to 4.3% from baseline, except in females aged 36-70 years who did not experience a significant change. Fat-free mass was significantly reduced in all subjects (P < 0.001), whereas percentage body fat was lower only in males by 2.5% (SE 3.2%) (P = 0.029) in those aged ≤35 years and by 1.1% (SE 1.5%) (P < 0.001) in those aged 36-70 years. Dietary intake was similar before and during Ramadan, except in males whose protein intake fell during Ramadan (P = 0.032). CONCLUSIONS: Ramadan fasting leads to weight loss and fat-free mass reductions. Body composition changes vary depending on age and sex.

Effect of Ramadan fasting on glycemic control in patients with Type 2 diabetes.

BACKGROUND: Although Muslim patients with Type 2 diabetes may be exempt from fasting during Ramadan for medical reasons, a high proportion of them fast. AIM: To investigate the association between Ramadan fasting and glycemic control in patients with Type 2 diabetes. SUBJECTS AND METHODS: A prospective cohort clinical trial was designed. Eighty-eight patients with Type 2 diabetes (45 male, 43 female, age 51±10 yr) who opted to fast for at least 10 days during the month of Ramadan were recruited. Fasting blood samples were taken at the beginning and end of Ramadan, and 1 month after Ramadan, to assess fasting blood glucose (FBG), fasting insulin, full blood count, glycated hemoglobin (HbA(1c)) and fasting lipid profile. Insulin resistance was estimated using the homeostatic model assessment. Anthropometrics and blood pressure were also measured. RESULTS: There was a significant deterioration in FBG and HbA(1c) (p=0.002 and p≤0.001, respectively) and significant improvements in HDL and LDL cholesterol and body mass index after Ramadan (p<0.001). Interestingly, HbA(1c) showed a reduction 1 month after Ramadan (9.4±2% at the end of Ramadan vs 8.4±2.5% 1 month after Ramadan; p<0.001). CONCLUSION: Results from this study showed that fasting during Ramadan deteriorated the glycemic control in Type 2 diabetes patients. This was more evident in patients using oral hypoglycemic medication than diet- controlled patients. However, Ramadan fasting had small positive effects on lipid profile and body weight.

The effect of a 12-week low glycaemic index diet on heart disease risk factors and 24 h glycaemic response in healthy middle-aged volunteers at risk of heart disease: a pilot study.

OBJECTIVE: To compare the effects of two energy-restricted healthy diets, one with a low GI and one with a high GI, on heart disease risk factors and weight loss in subjects at risk of heart disease. DESIGN: A 12-week randomized parallel study of low and high GI, healthy eating diets was carried out. SETTING: The study was carried out at the Hammersmith Hospital. SUBJECTS: Eighteen subjects were recruited by advertisement and randomized to one of the two diets. Fourteen completed the study but one was excluded from the final analysis. METHODS: At randomization, subjects were advised to follow the intervention diet for 12 weeks. Before randomization and on completion of the study, anthropometrics, fasting cholesterol and glucose blood tests and 24-h glucose measurements were taken using a continuous glucose monitoring system (CGMS). Statistical analysis was carried out using non-parametric tests. Median (IQR) are presented. RESULTS: A significantly different dietary GI was achieved in the low GI (median: 51.3 (IQR: 51.0-52.0) compared to the high GI (59.3 (59.2-64.0) (P=0.032) group. By week 12, both groups reduced their energy intake by: low GI group: (-)167 ((-)312-(-)123) kcal/day (P=0018) vs high GI group: (-)596 ((-)625-(-)516) (P=0.018) kcal/day, the difference between the groups being significant (P=0.010). However, only the low GI group lost weight ((-)4.0 ((-)4.4-(-)2.4) kg (P=0.018) whereas the high GI group did not significantly change in weight ((-)1.5 ((-)3.6-0.8) kg (P=0.463). By week 12, the low GI group also had a significantly lower 24-h area under the curve (AUC) (7556 (7315-8434) vs 8841 (8424-8846) mmol-h/l (P=0.045) and overnight AUC (2429 (2423-2714) vs 3000 (2805-3072) mmol-h/l (P=0.006) glucose as measured by CGMS. There were no differences in the other heart disease risk factors assessed. CONCLUSIONS: This pilot study provides some evidence that consuming a low GI diet in addition to weight loss and healthy eating may reduce cardiovascular risk. Other potential benefits of GI might have been masked by weight loss in the low GI group. Larger-scale studies need to follow.