The biggest inhibitor here is nervous development and mental understanding of complete force output. (onnit.com)
There is a disconnect between mental understanding and mechanical ability to do, and describing it in a way you think they would understand can actually be bad for them. (onnit.com)
They kind of develop a vague mental understanding of the amount of food they can eat, and they very often cook and / or order meal sizes that match this understanding they have in their head of how much food they think they need. (fitnessandpower.com)