if you're working out steadily and in a daily caloric deficit you will not gain nearly as much muscle mass as you're losing in fat.
maybe if you're on roids.
gaining 10lbs of pure muscle mass in 3 months is not realistic. re-examine your diet, and your caloric maintenance at your current weight, this may be obvious to you but it'll be less at 200 than it was at 250.
i'd suggest doing a little bit of research on fundamental physiology, and the basic functions of diet and exercise. i say basic cause diet and nutrition and physiology can be so extremely complicated and overwhelming, a lot of it i feel is useless to somebody who just wants to be healthy and fit, but a basic and well-rounded understanding will definitely enable you to be more efficient in reaching your goals.
This post was edited by Wretch on Mar 20 2017 12:30pm