It is kind of sad that there are so many people with no idea at all about nutrition, calorie counts etc.

Aside from the examples here, they will do things like get a huge, calorie-laden muffin at Dunkin Donuts and then pat themselves on the back because that's the healthy choice compared with a donut, right?

I think it's tough to critique other people's food though, unless they specifically ask. But I would assume that posting it on Facebook constitutes asking, in the sense that if you post it, you must expect people to comment. I'm not sure exactly what I'd say - maybe something along the lines of what Twinmomma suggested and say that it looked delicious but unfortunately, too much fat and calories to be healthy on my plan.