Homebru and Jack - my challenge is healthy eating. I think I've got exercise down fairly well. Not great, but OK. But it don't do no good when I eat junk.
After a fair amount of reading and helping a daughter with a very bad autoimmune disease, listening to all the doctors and nutritionists, I am very much bought into more natural eating and adding as many micronutrients as I can.
I am doing three weeks as a vegan.
The main thing I have figured out for myself is to think of what I ADD to my diet, not to focus on what to subtract. If I add food rich in nutrients, removing bad foods is easy.
I found that hunger is usually not really hunger, it is appetite. If you don't get enough colorful veggies, rich leafy greens, beans, colorful fruits, tree nuts, etc. your body is hungry. If you try to satisfy hunger with low-nutrient foods like potatoes and breads, you just crave more of them because you're not getting enough nutrition.
I stopped making eggs, bacon and cakes in the morning; now I have a vegan smoothie just like a hippie(that was hard to admit) every morning and I do not get hungry and I feel much better. No soy, no eggs, no wheat, no corn, no added sugars, no grains, no dairy.
After three weeks, I will become vegan-plus . . . . vegan plus meat! Lean meats, wild meats, birds, fish, etc. After all, I am a hunter. My daughter loves the term vegan-plus.
Also I avoid as much man-made stuff as I can. No diet sodas, try to go for organic meats that didn't grow up on chemically raised crops with pesticides, no farm raised grains, etc. I can't do so 100%, but I do try.
My challenge is sticking with this, as I travel a lot, and like the rest of us I shop in grocery stores filled with bad stuff and am surrounded by fast food joints.