[header] How to gain weight fast (for men ) [title] Eat more than three meals a day. [step] If you naturally have a really fast metabolism, eating three meals a day, no matter what's in them, isn't going to help you bulk up. Your body burns calories fast, so you need to feed it more than it can use up right away. 
That means eating not just when you're hungry, but throughout the day. Aim to eat five meals a day to gain weight.