A comprehensive systematic review indicates that intermittent fasting may not provide significant advantages for weight loss in adults with overweight or obesity when compared to standard dietary advice.
The analysis of 22 randomized controlled trials, involving nearly 2,000 participants, showed little to no difference in percentage weight loss from baseline between intermittent fasting methods and regular dietary guidance. The certainty of this evidence was rated as low due to potential bias and methodological limitations.
Similarly, intermittent fasting appeared to have a negligible impact on achieving clinically significant weight reduction or improving quality of life, with uncertain evidence regarding adverse events.
Compared to no intervention, intermittent fasting likely produced only small, not clinically meaningful, reductions in weight. Crucially, none of the trials reported on participant satisfaction, diabetes status, or broader comorbidity measures, leaving key clinical questions unanswered.
Most studies assessed outcomes within 12 months, limiting conclusions on long-term sustainability. The review authors emphasize that intermittent fasting and conventional calorie-restricted approaches yield similar short-term results. Therefore, the decision to adopt intermittent fasting may hinge more on individual preference, practicality, and long-term adherence than on clear outcome superiority.
Despite widespread popularity, this synthesis of trial data suggests intermittent fasting's effects are broadly comparable to other structured dietary approaches. Clinicians and patients should consider personal readiness, lifestyle compatibility, and sustainability when selecting a dietary strategy. Future research needs to explore longer-term outcomes and impacts on comorbid conditions.