It doesn't have to be this complicated with all the lowfat, nonfat, low carb, no carb, vit. supplement things that everyone's pushing.
My folks are 74 and 76 years old and used to be pretty sick, even though they always exercised, ate low fat everything, etc.
Fifteen years ago they went strict veggie, mostly raw fruits and vegetables, nuts, legumes, whole grain bread sweetened with raw honey, olive oils, vinegar, filtered water and started drinking fresh carrot juice every morning. They started jumping on rebounders every day and a brisk walk of about 2 mi. each day(which they already did!) All their illnesses went away within a couple of months and haven't come back. I could tell you so much about the changes and evidence of good health in these folks but it would take a while. They don't eat any animal byproducts at all now.
Now, as a nurse, I was skeptical at first...then I started seeing the tangible results of this change and I was and still am very impressed.
Now I don't go with the carrot juice, but I started eating somewhat like them and it is great! I ate as much as I wanted and I never felt hungry. The food was so tastey that I was never bored with the taste and it never felt like I was dieting. Actually, its not even a diet, just a lifestyle change.
My kids and I haven't had to take an antibiotic or had any illness for about 10 years now. And we aren't even half as rigid as my folks with this...we just avoid dairy, store bought meats (we have deer and my chickens, if we want meat), preservatives, complex sugars.....drink alot of fresh water, make our own whole wheat bread, lots of fresh veggies, etc.
It can be done, but don't expect people to understand....most folks don't like people to be different, especially in a social situation. Lot of social eating out there!