Ahh, the eternal debate.
I am definitely of the opinion that there is no such thing as moral value for food. Now, just because I have this opinion doesn't mean I always practice it. It can be very challenging to not have a reaction to eating the salad versus the burger or having the cake over the fruit cup. If you have dieted, you know the significant values (Points, anyone?) placed on food.
If you want to value food at all, I definitely support the notion of looking at what may be good or bad for you. This means what foods make you feel good, which ones make you sick, or which ones you just plain don't like. For example, for me good foods include:
Bad foods (particularly ones that upset my stomach) include:
Chewy fruit candies (Mike & Ike's)
Most frozen vegetables
Obviously, they are morally "heavy" foods on both lists but some "healthy" foods make me sick. I find this an easier and less stressful perspective to take with food, as it forces me to look at my own needs and limitations as opposed to societal values on food.