You will lose weight by fasting so if you have overweight it might be beneficial to do something like 5:2 fast diet (https://amzn.to/2TsutXV). Other than that there is not much benefit of fasting.
Fasting can be unhealthy in some cases when you eat or drink to less or for people that are already skinny. It's only beneficial when you want to lose weight but there are also other ways like sporting more or eating healthier. Or a combination of those things.