Is intermittent fasting effective for weight loss?

It works about as well as continuous calorie restriction — the benefit comes mainly from eating less overall, not from meal timing magic. It suits people who find rules easier than counting. It's unsuitable in pregnancy, eating-disorder history, or on insulin without medical supervision.

Head-to-head trials generally show similar weight loss when calories are matched. The advantage is adherence for people who prefer a rule over daily tracking.

Avoid it if you are pregnant or breastfeeding, have a history of eating disorders, are underweight, or take insulin or sulphonylureas without your doctor adjusting the regimen.