Intermittent Fasting: Efficacy, Safety, and Its Impact on Body Weight, Glucose Metabolism, and Gut Microbiota

Intermittent fasting (IF) has gained significant attention as a nutritional strategy with potential health-promoting effects. It typically involves periodic restriction of calorie intake or limiting the daily eating window. Growing scientific interest has led to a wide range of clinical and observational research exploring its biological and metabolic impacts. Existing studies suggest that IF may positively influence metabolic health, weight management, and cellular processes. However, the breadth of findings varies, and questions remain regarding its long-term safety and effectiveness across diverse populations, especially individuals with chronic conditions. A comprehensive evaluation of the current evidence is therefore warranted. An analysis of 55 publications, including clinical trials, observational studies, and review articles, was conducted. These sources were examined to assess the effects of various forms of IF on metabolic health, diabetes-related outcomes, gut microbiome composition, and broader physiological functions. Across most studies, IF was associated with moderate but clinically meaningful weight loss, enhanced insulin sensitivity, reductions in blood pressure, and improvements in lipid profiles. Some evidence also pointed to beneficial changes in gut microbiota, decreased oxidative stress, and increased autophagy activity. Comparisons with traditional caloric restriction indicate similar levels of effectiveness and safety, with IF potentially offering better adherence for certain individuals. Despite these promising outcomes, the current evidence base lacks long-term studies and comprehensive evaluations in specific clinical populations, limiting conclusions about sustained benefits and generalizability. IF appears to be a promising approach for the prevention and management of obesity and metabolic disorders. Its combination of physiological benefits and relative ease of implementation makes it an appealing strategy. Nonetheless, further long-term and population-specific research is needed to fully establish its safety, durability, and applicability across diverse groups.