Oddly I just watched a video about what an overweight person does not want people to say to him. The very first thing was the comments about his food. He said if he orders a regular meal, fairly unhealthy, people might comment. Like "Are you going to eat all that? Why did you order that?" But if he orders a salad he gets comments too like "Why a salad? Are you trying to lose weight?" There is no winning. There will always be comments.

So I would say based on this, commenting on food is a no-no. Like if you single someone out and do this.