Not sure if I’m being unreasonable about this. It’s a very touchy subject for me as it’s something my parents would called me, and even today I really struggle with my weight and body image. It’s something I always vowed to never put my lovely little one through.
DH was eating a bar of chocolate, DD (almost 3) wanted some but he finished it. I remembered I had a kinder egg in my jacket pocket as I’d bought it at the shop yesterday. I went and got it for her and as soon as DH saw it he said (in quite a nasty way) “those chubby cheeks don’t need any more chocolate”. I just responded “oh well lucky I wasn’t giving it to you” back to him to make it into a joke and gave it to her, but that comment really hurt me. DD is not chubby or fat, she’s a perfectly healthy weight! When I spoke to him afterwards about it and asked him not to say things like that to her he told me I was being ridiculous and his parents said the same thing and he turned out just fine. 
Not sure if it’s relevant, my MiL is also very critical of weight in general and will say very horrible things to my SiL that I can see have a massive effect on her. So I can see that it’s something he grew up and although it didn’t have an effect on him, it has clearly had an effect on his Dsis.
Am i overreacting here? Surely all children have chocolate every now and again