overweight 3 year old

My DGS has his health/progress check this coming week he is 2.5 yrs (30 months)
So your DGC would probably have had a health check about 6+ months ago.

Thanks for this advice. It has echoed my inner thoughts - that it's better not to interfere. Parents are vegetarians and I think that our grandchild doesn't really appreciate the sort of food they eat. Does anyone know if health visitors (are there any these days??) still do 3 year old checks?

I really wouldn't say a word at this point. Once he starts school there will be less opportunity for for random snacking plus, hopefully, plenty of exercise. It's really not worth risking your relationship. If you stay friendly you'll be able to keep an eye on him.

Tread very carefully.
I had a very active 4yr old DD. (swimming, dancing classes etc)
My Mil passed a comment in front of my DD that she was looking a bit chubby (IMO she wasn't).
My DD has neither forgotten or forgiven the remark and it damaged her relationship with her grandmother.

Unless your DS and DIL are deaf and blind they are aware of healthy weight , we are bombarded with information in the "Media" on healthy eating and the dangers of snacking and sugar consumption ! Please don't get involved ! You will find there is NO way to criticise parental modes and he will probably grow out of it as he gets older and gets to pre school

Oh! Dodgy ground that!!! I suppose it depends what sort of relationship you have with your daughter in law. I think that my GSs have always had too much sugar, but I have an extremely independent daughter. It's the way I brought them up, so can't really complain that I can't tell her how to run her life!!!