Intermittent fasting: Intermittent fasting may not deliver the weight-loss edge many people expect, according to a new evidence review that compared fasting plans with standard dieting and with no dietary changes.
The reviewers pooled results from 22 randomised trials involving 1,995 adults with overweight or obesity, across multiple countries and settings. Participants followed different fasting approaches, including alternate-day fasting, the 5:2 pattern, and time-restricted eating. Overall, the analysis found that weight loss from intermittent fasting was broadly similar to conventional calorie-reduction advice, with no clear advantage for fasting over more traditional diet plans.
Also Read | Eating within an 8-hour window eased Crohn’s symptoms in small trial
Compared with doing nothing, fasting produced only a small reduction in body weight, around 3% on average, a level that falls short of the 5% loss often used as a benchmark for clinically meaningful change. Most of the studies were short-term, tracking outcomes for up to 12 months, limiting what can be said about long-term results or sustainability.
Beyond the modest change on the scale, the review found no strong evidence that intermittent fasting improved quality of life more than other dietary approaches. The researchers also highlighted gaps in the available evidence, noting that many trials were small, varied in quality, and often measured outcomes differently, making firm conclusions harder.
Experts not involved in the review said intermittent fasting remains difficult to study because “intermittent fasting” can mean different things in different trials, and timing may matter. Some point to early research suggesting fasting could influence metabolic pathways, but they note those signals have not consistently translated into clear, durable benefits in human weight-loss trials.
The overall takeaway from the review is that intermittent fasting is not a magic shortcut for weight loss. It may still help some people reduce calories and structure eating habits, but as a population-level strategy, it appears to perform much like standard dietary advice, and only slightly better than making no change at all.
