They make you feel complete when you eat them.
The amount of energy you get from them is so incredible that you feel life force flowing through your whole body.
Get the picture?
This is just a strating point.
You can follow up on that idea and write whole poems dedicated to the joy of eating healthy ;)
This will absolutely totally recreate a new set of emotional associations with healthy foods
http://vitalcoaching.com/stayfit.htm