Our perception of appropriate portion sizes has gotten way out of control, and as you have noted, that seems to be part of the problem. Do you think he would be receptive to some of the portion-size tricks that are out there (e.g., a serving of meat is the same size as a deck of cards, cheese about the size of two dice, etc.). Maybe getting the right portion size would be more gentle a change than saying he has to cut out foods entirely, at least at first.
Here's one example of the guidelines:
NCPAD:Health Promotion:*Estimating Serving Sizes
I agree with Terri in that knowledge is power. As any of us here knows, it only takes a little bit to get "hooked" into wanting to know more about what exactly we are putting in our mouths...maybe something will spark for him soon.