My step father feels he has to comment on what's on everyone's plate. Nothing ever complimentery.
"Wow, that's a lot of saltly, fatty, whatever stuff you have there." "Are you sure you want that much." "Oh I wouldn't eat that."
or.."You continue eating...I didn't have as much as I only ate the healthy stuff."
Most of the time this is in a private home so it's always met with complete silence and more than a few eye rolls.
But.....the silence finally got broken. Hey I hit 50 this year and found that I don't take as much rudeness than I used to.

We were at a buffet type dinner (we were guests at a Bar Mitzvah) and I brought back desserts from the dessert table.
Before I could do anything...be it share it (which was the intention) or take a bite, he said it a loud voice...."Did you leave any for anyone else? That's too much for one person. I wonder how many calories are on that plate".
(Now this was after all the normal rude comments....just louder than normal. And we were in mixed company, He was drawing stares!)
I put on my deadly calm smile and replied quietly, "What would really be nice is if one could actually be able to enjoy their meal without someone commenting about what's on their plate."
He said with nervous laughter.."oh you can enjoy your meal but I'm going to razz you about it." I again calmly replied..."The two cannot mix."
He finally shut up. We'll find out at Christmas if he really realized how rude he was being.