after fast?

this is my 3rd day on my fast and i have lost five pounds. i need to lose about 20 more but my question to all who have answers is this, when i come close to my goal weight should i start eating little by little to rev up my metabolism . how do you keep all of the weight off . i am 20 years old and i do belong and go to the gym less often now because i an fasting but i just need some facts. thanks, allie Tweet