What the science actually says
Intermittent fasting works about as well as eating less every day. Its advantage is that many people find it easier.
For weight loss
Trials comparing intermittent fasting with a regular diet of the same calories show similar results. In a large trial in China (2022), eating within 8 hours plus calorie restriction did not beat calorie restriction alone after a year. In another (2020), doing 16:8 without changing anything else produced very small weight loss.
So what is it good for?
For many people it is a simple way to eat less: fewer hours, fewer chances to snack, a clear rule. If you find it easy to keep up, it is a good tool. If it makes you miserable, it is not better than other approaches.
Other effects
Some studies show improvements in insulin sensitivity, blood pressure and other markers, but they are usually small and short. Many striking effects come from animal studies.
Why we tell you this
Because apps that promise miracles make you feel like you are failing when nothing magical happens. We would rather you know what to expect.
Sources
- Liu D et al. Calorie restriction with or without time-restricted eating in weight loss. N Engl J Med. 2022;386:1495-1504.
- Lowe DA et al. Effects of time-restricted eating on weight loss and other metabolic parameters: the TREAT randomized clinical trial. JAMA Intern Med. 2020;180(11):1491-1499.
- Cioffi I et al. Intermittent versus continuous energy restriction on weight loss and cardiometabolic outcomes: a systematic review and meta-analysis. J Transl Med. 2018;16:371.
General information; not a substitute for a health professional.