Intermittent fasting leads to weight loss and metabolic benefits, but the effect is almost entirely due to a lower calorie intake, not the fasting itself. Randomized studies show no clinically relevant difference compared with conventional calorie counting. Whether it is worth pursuing depends mainly on personal preference and long-term adherence.
Intermittent fasting works, but the secret is not in the fasting itself: the benefit comes almost entirely from eating less overall. Two recent reviews of randomised trials show that the outcomes for weight and metabolism are virtually identical to straightforward calorie counting, with at most a small difference in favour of fasting. That small difference was statistically detectable, but it is not large enough to transform your life.
Whether it is worth it therefore depends mainly on one thing: does this eating pattern work better for you personally than another approach? For people who struggle with calorie counting but find it easy to live with a fixed eating window, fasting can be a smarter strategy -- not because it is biochemically more special, but because you stick with it. That practical argument is real.
Two situations in which you should think carefully before starting: if you use medication for diabetes, an adjusted eating schedule can affect your blood sugar at unexpected times, and that warrants a quick conversation with a doctor. And in cases of underweight, pregnancy, or a history of eating disorders, it is simply not suitable. For everyone else it is safe to try. Effects on lifespan have not yet been demonstrated in humans, so if that is your primary goal, the evidence for it does not yet exist.
Moderate evidence, 2 source(s); the direction is probable but not firmly established.