Actually there is something called starvation mode. I actually had my two week post op today and met with my surgeon and nutritionist and they brought up starvation mode when I complained about my stop in weight loss. When you workout you gain muscle so that causes the stall and possible weight gain of a couple pounds before you actually start losing weight. Don't add to or take away from your diet with consulting your team first. Trust me that's what I did and I am medical for over 15yrs. Just keep following your diet and you will get past this no problem. By the way 15lbs is awesome congrats. Remember the small victories and don't be discouraged