Effectiveness of Ramadan diurnal intermittent fasting and concurrent training in the management of obesity: is the combination worth the weight?

BACKGROUND AND AIMS: We investigated, in men with obesity, the efficacy of the combination of two strategies (Ramadan diurnal intermittent fasting 'RDIF' strategy vs RDIF plus concurrent training program 'RDIF-CT' strategy) known for their positive impact on body composition and then we explored the possible impact on metabolic and inflammatory biomarkers. METHODS AND RESULTS: Twenty obese men, age: 31.8 ± 7.05 years, BMI: 33.1 ± 4.2 kg m-2, performing regularly RDIF, were randomized into two groups: RDIF-CT (n = 10) and RDIF without training (RDIF-NCT) (n = 10). The RDIF-CT group participated in High intensity interval training (HIIT) program combined with resistance exercises for 4 weeks. Body composition, blood glucose, lipid profile, liver biomarkers and inflammation were assessed before and after 4-week RDIF. Both groups showed a significant decrease in weight, fat mass (FM), fat percentage (Fat%) and waist circumference (WC) and an improvement in blood glucose, lipid profile and inflammation. Fat free mass decreased significantly in RDIF-NCT (p < 0.05) while remaining unchanged in RDIF-CT. However, RDIF-CT induced greater improvements in body composition (i.e., weight, FM, Fat% and WC (p < 0.05, p < 0.01, p < 0.01 and p < 0.05; respectively)) as well as greater decrease in lipid biomarkers (i.e., TC, TG and LDL (p < 0.01 for all)), inflammation (i.e., CRP (p < 0.05)), and liver damage (i.e., ASAT, ALAT and Gamma-GT (p < 0.01, p < 0.05 and p < 0.001; respectively)) compared to RDIF-NCT group pre-post intervention. CONCLUSIONS: Our results suggest that a combination of RDIF and CT induces greater changes in body composition, lipid profile, inflammation and liver biomarkers compared to RDIF strategy alone. CLINICAL TRIAL REGISTER: PACTR202203475387226.