METABOLIC AND LIFESTYLE DETERMINANTS OF FASTING IN ADULTS: AN INTEGRATED ANALYSIS OF BIOMARKERS, FOOD FREQUENCY, AND ACTIVITY PATTERNS

Abstract

This retrospective cross-sectional study, conducted between November 2025 and April 2026, evaluates and compares the physiological and metabolic impacts of Ramadan fasting and intermittent fasting. The assessment focuses on anthropometric, biochemical, metabolic, and hematological parameters, while also analyzing the influence of lifestyle (diet and physical activity measured in MET-minutes/week). Data were collected through questionnaires and fasting blood analyses (statistical significance threshold set at p < 0.05) from adult volunteers residing in Tlemcen (Algeria) and Nouakchott (Mauritania). The study included 48 participants (35 women, 13 men; mean age: 31.44 ± 12.14 years) out of 136 individuals contacted, representing a participation rate of 35.29%. The results show a clear improvement in anthropometric outcomes, characterized by a significant reduction in body mass index (BMI) and waist-to-hip ratio. At the metabolic level, decreases were observed in blood glucose, total cholesterol, triglycerides, and LDL-cholesterol, alongside a beneficial increase in HDL-cholesterol. Biomarkers of renal function (urea, creatinine), hepatic function (AST, with ALT remaining stable), and inflammation (CRP) also improved. Finally, the hematological profile shows an increase in red blood cells, white blood cells, and platelets. Inter-population comparison indicates similar benefits despite differences in dietary habits. Regarding intermittent fasting studied in 33 Mauritanian participants (24 women, 9 men; mean age: 31.63 ± 13 years), intermittent fasting induced a significant reduction in body weight, BMI, and waist circumference. Glycemic and lipid profiles improved (increase in HDL-cholesterol), as did renal and hepatic functions, evidenced by decreases in urea, creatinine, and transaminases. Both Ramadan fasting and intermittent fasting exert highly favorable effects on nutritional and metabolic health. By improving glucose and lipid profiles, enhancing body composition, and positively modulating inflammatory, renal, and hepatic markers, these practices appear to be relevant tools for preventing metabolic disorders, provided they are combined with appropriate lifestyle habits.