Confrontation on eating

My son is my life. I love him to death, the only problem is that he has gained weight. I am afraid, that due to our family history, his weight might not go away as easy as it came.

When I try to talk to him about eating habits, he gets really frustrated and confrontational, almost like I am attacking him. I am trying to talk to him from a mom's point of view and the view of someone who has battled food.

He gets defensive and doesn't want to hear it, but he does.

I watch him, he is self-conscious, but also is just his quiet self. I don't want him to suffer like I did and I am completely at a loss on how to talk to him. I want him to be healthy and happy. I don't want him to go through what I have suffered with.

How do I confront him and talk to him without him getting so upset with me? I want him to understand that I am trying to help him.

Any suggestions for a mom in a corner... mentally...