For older adults navigating the twin threats of excess adiposity and age-related muscle loss, a dietary intervention that reduces weight without eroding lean mass would represent a meaningful clinical advance. Most fasting research has centered on younger populations, leaving a gap in evidence precisely where the metabolic stakes are highest — making this systematic review with network meta-analysis a timely contribution.
Drawing on 31 studies published through June 2025 and identified across PubMed, Scopus, and ScienceDirect, researchers evaluated intermittent fasting (IF) protocols in adults aged 60 and older. Seven randomized controlled trials (RCTs) were eligible for a network meta-analysis comparing time-restricted eating (TRE), the 5:2 method, Islamic Sunnah fasting (ISF), a Healthy Living Diet, and usual diet. Among the protocols assessed, ISF and TRE 16:8 emerged as the most effective for anthropometric outcomes: ISF was associated with a mean weight reduction of 2.36 kg and a BMI decrease of 0.81 kg/m², while TRE 16:8 yielded a 1.92 kg weight loss and 1.01 kg/m² BMI reduction — critically, without detectable lean mass loss. Cardiometabolic markers, mental health indicators, and cognitive function were addressed in a narrative synthesis only, as available RCT data were insufficient for formal pooling.
The finding that lean mass was preserved is particularly notable given that sarcopenia — progressive skeletal muscle loss — accelerates after 60 and is independently linked to falls, frailty, and mortality. Prior concerns that caloric restriction strategies might worsen sarcopenia in this cohort appear less warranted here, though the caveat is significant: only seven RCTs contributed to the network meta-analysis, a modest evidence base that limits the precision of effect estimates. The narrative-only treatment of cognitive and cardiometabolic outcomes reflects a genuine literature gap, not an analytic choice, and underscores how immature the evidence remains for older adults specifically. Inclusion of observational and pre-post studies in the narrative synthesis introduces heterogeneity that could color the broader conclusions. This review is best characterized as confirmatory-with-caveats — it supports cautious optimism about IF safety in older populations while clearly delineating how much rigorous trial data remains needed.
