I am 22 years. Weight 45kg. Height 5'4".female. Very lean. I want to become little bit fat with nice structure with in 1 month. How?

You can't be sure the 'little bit fat' will go on where you want it, honey. That is an almost impossible achievement. You could gorge yourself with fattening foods for one month and the next month (when the weight will show up) find that you have really ugly hips. You obviously have a purpose in mind, but I would say be happy with what god gave you.

Tick