I think you have to let go of what your S' are eating at your X's. Something you don't have control over. Do what you can, like mention to your PC, and then let it go.
Just like everything, I think it's important that you model healthy lifestyle/eating/exercising. The job I have now makes you realize how important it is to be healthy. I directly see every day people that have been severely impacted by obesity, smoking, and/or drinking. Motivates me to not wind up like that!
How are you finding out all this info about fried foods, donuts, ice-cream, at your X's house? If one or both of your sons is going on about this; I think it would be good to change the topic. Just relate to what is going on in your house. I also think if your X and Jabba continue to eat like that; they're going to have health problems soon, and your S will see that too.
Prayer can't hurt either. I'll add this to my list...
