Hi there!
Same issue here! I'm on windows 7
It seems like my sims are especially attracted to spoiled food, it's very odd. If i call everyone to meal and there is spoiled food in the house, they will go for it instead of the fresh cooked meal. If i ask them to clean it up, they will pick it up and put it on the side. I actually have to drag it to the bin or a sink myself.
I have noticed that it doesn't happen all the time too, I don't see a pattern.
And I agree that the game doesn't make much distinction on food preferences, and I find that particularly annoying for vegetarian sims. When you use the have leftovers interaction, the vegetarian sims will pick up a dish regardless of if it's a vegi meal or not. Same issue when you call for a meal and there's several dishes on the table, some vegi some not. The vegetarian sims will pick a dish randomly it seems, as a "normal" sim would, whereas it should taget what is appropriate for him.
Again, annoying... But I believe that's the way the game is set up, more than a glitch of any sort.