Some kids have a more rebellious nature than others, parents would know, so it would be obvious that when they are being denied sweets, of course they'll gorge themselves when they sneak it or finally have access to it. Then, other kids may have restrictions, but when given the chance to eat snacks away from mom's eye, they can't be bothered to binge. Maybe they just don't have a sweet tooth. Perhaps the need to defy the folks is not so strong in them.

An observation I made is, if you've got a parent who is extremely mindful of what they eat & tries to instill the same eating habits in their kids, there's a lot of focus in the household placed on food. It's a fine line isen't it?: how to teach good eating habits without it becoming a food obsession or eating disorder. How many times does a young child have to hear something's bad for them before they start to question, "hey, is it really so bad? I want to know for myself! Let me at it!"
For me, this certainly was true with the boys I was warned not to date!

(but seriously.)

Kids are the same as adults - they learn that in life, many "bad" things are "good".