Verified answer

They are kids, very young. Don't worry about the weight. If you make your son lose weight, he won't develop correctly [ my doctor told my mother that]. When I was 4 I weighed 30 pounds and still wore 18th month clothes. The next summer, I went for 18th month clothes, to 3T. I was still very healthy. He will thin out naturally. He is going to be bigger, because he is a boy.

As kids, you shouldn't interfere with their growing habits. Being overweight or underweight isn't really a serious problem as a child, and trying to fix something that doesn't really need it will make it worse. Just let your kids go through the course of growing and everything will fix itself eventually!