What are the causes of hair loss in men?

You know, there can be plenty of reasons. We can use different shampoos, oils, take some medicines, but we cannot get the best result if we don't care about nutrition and sleep patterns. My father was struggling with this problem for two years until he started changing his harmful habits: no fatty food, more physical activity, going to sleep before 11 p.m., etc. I should say that it really helps.