Bold claim up front: intermittent fasting may not help you lose more weight than simple, standard dieting advice. And this is where the discussion gets nuanced. A new review looked at 22 earlier studies, involving about 2,000 adults, to see if short-term intermittent fasting (up to a year) outperforms conventional dietary guidance or no guidance at all. The takeaway is that intermittent fasting usually makes little to no difference for weight loss or quality of life compared with traditional dieting. It also showed little impact when compared with no guidance, though the evidence about quality of life remains unclear.
What counts as intermittent fasting? It covers several patterns, including:
- Eating only during a fixed daily window
- Fasting on specific days of the week
- Alternating normal eating days with very low-calorie days
The researchers noted that, overall, intermittent fasting didn’t beat standard calorie-cutting and healthier eating advice. It also didn’t show clear advantages over having no guidance, although the effect on quality of life wasn’t definitively determined.
There is some caveat in interpreting these results. The team described their confidence as only “moderate” when comparing fasting with no advice, and they were less confident about other outcomes. A major limitation across the included studies is that many used modest methods and small participant numbers, making it harder to pinpoint true effects.
The review, published in the Cochrane Database of Systematic Reviews, calls for more research into how intermittent fasting might affect other health areas beyond weight, such as type 2 diabetes status and other health conditions, as well as how satisfied people feel with the approach.
Additionally, there are many fasting formats in practice, and more detail is needed on how these patterns affect men and women differently, as well as people with varying body mass indexes (BMIs) and across different countries. The analyzed studies drew participants from Europe, North America, China, Australia, and South America.
Commenting on the findings, Dr. Baptiste Leurent of University College London noted that, taken together, the studies “provide a clear indication that intermittent fasting offers little benefit.” He added that there remains a common gap between public perception and what the scientific evidence shows.
Prof. Keith Frayn of the University of Oxford echoed this sentiment, noting that intermittent fasting has been widely marketed as a weight-loss shortcut, often with claims of metabolic “special effects.” The study suggests such claims may have little relevance, reinforcing the idea that there are no quick fixes for overweight or obesity beyond managing calorie intake.
Beyond weight, it’s widely recognized that many people find intermittent fasting appealing as a way to avoid weight gain, though this particular review did not study that aspect.
There’s also a real-world backdrop: about 1.6 million UK adults are estimated to be using injectable weight-loss drugs like Wegovy and Mounjaro, mostly via private prescriptions rather than NHS access. A recent study highlighted that stopping these injections can lead to rapid weight regain—up to four times faster than stopping traditional dieting and exercise.
In short, while intermittent fasting remains popular, this body of evidence suggests it does not outperform standard dieting guidance for weight loss on average, and it prompts a thoughtful discussion about where its real value lies and what further research might reveal.
