I never had a weight problem until after having kids and then my body would get stuck at the pregnancy weight like it had a new set point. I would give birth to 20 pounds of stuff and a week or two later weigh what I did when I went into labor! But, once I got it off (which took some work) it would stay off. I have never been skinny but generally hang in the 170-180's and always athletic...when I hurt my back and couldn't walk, I gained, anytime I cut out the exercise I gain but if I am exercising I dont usually have to worry about what I eat.