There should be a yoyo option. I don't think childhood is the only place your weight is going to change.
I've been mostly thin, but I have yoyo'd. If i get sedentary I have found I will gain weight. I'm itty bitty, 5'1 and small boned. I was thin right up until the summer in between junior high and highschool. I stopped "playing" and I was always stuck at home watching my 5 younger brothers and sisters, no sports. I steadily gained weight until the summer after my Junior year. I got my drivers license and a job, and up off my butt so I lost weight my senior year. I had been prob 125/130 before I got that job. That doesn't sound like much but on a 5'1" small frame you don't much body to spread it around lol, I was a little chubby, not fat, just a pudgy size 10. By the end of my senior year I was down to 115. I stayed that weight until I was 21. When I was 21 I lost my job on a Monday and got a DUI that saturday, bad week. So i had no license and no job for at least 6 months....and a buddy of mine would take me out drinking almost every night. All that sitting around and all those beers I was back up to 130 in no time. That bad week was in Aug, then the next spring I got a job landscaping, and shed the weight by the end of the summer. That winter right before my 22nd bday I met the guy I married and had a baby at 23, after nursing him (best diet ever btw) I got to 102, had another baby at 25, went right back down to 102. Stayed between 102-110 ever since, I'll be 38 next month. Well the last year I've rarely gotten over 100. Got really stressed out, man problems, last January and lost weight, ended up 97 pounds. I need to gain a little more weight I've been a size 3 for forever now, but now all my pants are too big. I should really be in a size 1, I broke down and bought one new pair of work pants in size 1 so they fit. I need to gain a little weight because I don't want to buy a bunch of new pants, and I have a case of saggy britches.
In the past 20 years I have never had a job where I sat down, between that and working out semi regularly I've kept any weight off but I know if I ended up being less active I'd gain weight quick.