I have been really anorexic thin & as soon as I gain any weight I get that tummy thing. 5'1" there isn't much places for weight to go other than there. I find however when I cut out all junk food I immediately loose because I'm so active even at my age & with all the injuries I've had. I still ride horses, climb fences. Physically I get around like I have all my life. I can't imagine life not being this way but could see how inactivity could cause weight gain