I had the same question arise over whether or not to limit food when one of my DCK was 1-2 years old. She would easily eat 3-4 times the amount of the other kids (and I had all good eaters) and I was very reluctant to limit her food. She is now 4.5 yrs and overweight....starti ng school this year and I worry for her being teased by the other kids. I'm really not sure if her eating is the reason or if it is some combination of genetics/body type as well.
I have a DCK starting in September who is 7mo now and his mum has said he would not stop eating(drinking) so they do limit his bottles to a reasonable amount.