Intermittent fasting has been shown to reduce overall calorie intake by 25% with alternate day fasting as well as the 5:2 protocol, in which fasting takes place on two separate days of the week.
By reducing overall calorie intake, weight loss occurs. However, just like anything, if you don’t stick with it long-term, the results will be temporary.
There is also some research that fasting supports healthy aging and extends lifespan, but most of the research thus far has been done in animals.