It’s not that he disliked Noah’s eating habit, but he was still two years old, and his overeating habits would affect his health;

he let Kate eat whatever she wanted because it was good for her and the baby; also, Kate knew her limits, it would not affect her health, but Noah was different.

He understood Nina’s worry. When she was alone in the M country, she let Noah do whatever he wanted; she was a single mother; after all, no one was there to teach her.

But as a brother, he always wanted her wellbeing; for her safety, he kept her away. Still, now Nina and Noah are his family. Even in the future, Nina will have her own family.

He wants to keep Noah to himself as his son; he wants to give Noah everything he would give his son.