Lift 200lbs how?
No excess fat you say? You were 5% body fat or below?

Incredulousness aside: eat less, exercise more. Best thing you can do is go lift some weights with some cardio thrown in for good measure. Barring that, you're going to have to do a lot of bodyweight exercises and a lot of cardio.

It won't be easy, so don't give up if you don't like how things are progressing after a couple weeks.