I think it's a great thing to teac young children to learn to eat healthy, keep consistent patterns and to teach them about what foods to avoid.

My only concern is that you do NOT refer to his eating habits in any way as a "diet" or something that he "needs" to do in order to lose weight. I would just refer to it as a family effort to keep ourselves more healthy so we can all be more active and happier. Slimming down is a bonus!

Little kids pick up on that stuff without letting on, and that little seed stays in there as they grow into obese adults because they were "dieting" since age 10. Make it fun...loosen it a little when he wants to...emphasize how your bodies are becoming healthy....

You're a great grandma!