Is Intermittent Fasting Useful for Weight Management?
Intermittent fasting is widely promoted as an effective way to lose weight. But does the evidence support the hype?
As a specialist weight-management dietitian, I think the answer is more nuanced: intermittent fasting can be a useful approach for some people, but it does not appear to be superior to other evidence-based approaches to weight management.
What does the latest evidence show?
A Cochrane review published in February 2026 included 22 randomised studies involving almost 2,000 adults living with overweight or obesity. When intermittent fasting was compared with traditional dietary advice, the review found that it “may result in little to no difference in weight loss.” The review also found little to no difference in quality of life.
The authors highlighted an important limitation: most studies were relatively short term, so there is still limited evidence about the long-term sustainability of intermittent fasting.
This finding is consistent with a major 12-month randomised trial published in the New England Journal of Medicine. Participants following an 8-hour eating window lost weight, but there was no significant difference in weight loss compared with conventional calorie restriction.
So, does intermittent fasting work?
It can. For some people, having defined eating times may reduce grazing and evening snacking or provide a simple structure that makes an appropriate energy intake easier to maintain. For others, fasting can increase hunger, lead to overeating during the eating window, interfere with social eating or simply be difficult to sustain.
The important point is that intermittent fasting is a dietary structure, not a magic mechanism for weight loss. The overall quality and quantity of food, energy intake, nutritional adequacy, physical activity and long-term adherence remain important.
Is it suitable for everyone?
No. Intermittent fasting may not be appropriate for people with a current or previous eating disorder, during pregnancy or breastfeeding, or for some people taking medication or managing conditions such as diabetes. If you have a medical condition or take medication, seek individual advice from an appropriately qualified healthcare professional before making significant changes to your eating pattern.
My dietetic perspective
I don't recommend intermittent fasting simply because it is fashionable. Instead, I consider whether it is safe, nutritionally adequate, appropriate for the individual and sustainable over time. Some people may find time-restricted eating fits their lifestyle very well. Others may achieve their goals more comfortably with regular meals and snacks. Neither approach is inherently better for everyone.
The bottom line
Intermittent fasting may be a useful option for some people, but current evidence does not show that it is superior to conventional dietary approaches for weight management. The February 2026 Cochrane review provides a useful reminder that sustainable weight management is less about finding a “perfect” diet and more about finding an evidence-informed approach that works for the individual over the longer term.
Key references
Garegnani LI et al. Intermittent fasting for adults with overweight or obesity. Cochrane Database of Systematic Reviews. 2026; Issue 2. CD015610.
Liu D et al. Calorie Restriction with or without Time-Restricted Eating in Weight Loss. New England Journal of Medicine. 2022;386:1495–1504.
