Impact of intermittent fasting regimens on circulating markers of oxidative stress in overweight and obese humans: A systematic review of randomized controlled trials

Intermittent fasting (IF) is proposed to elicit beneficial effects similar to calorie restriction including reduced oxidative stress. Oxidative stress can exacerbate and/or promote the development of metabolic-related complications and is thus an important outcome of interest in relation to obesity. In this systematic review we sought to evaluate the effect of IF regimens on circulating markers of oxidative stress compared to a continuous feeding pattern in overweight/obese adults. PubMed, SCOPUS, ProQuest, and Cochrane databases were searched for randomized controlled trials studying the effect of IF on measures of oxidative stress up to February 21, 2021. Independent extraction of articles was conducted by two authors using predefined search terms and restrictions/filters. Six articles, including 355 subjects, met eligibility criteria and were included in the present systematic review. The methodologic quality of each study was appraised, and the body of evidence was assessed. The studies were heterogenous, which precluded a meta-analysis, cohesive aggregation, and conclusions on effect size. All were rated high in quality with three reporting significant decreases in measures of oxidative stress. Although more research is needed, this limited body of evidence suggests that IF can impact oxidative stress.