I have several friends who are in the fitness industry, literal models of self-discipline (see their guilt-free snack ideas, above!). You want to know what they say? Maintaining a healthfully slim and strong body - especially in our convenience-loving and sedentary society, with all its delicious and fatty and salty fast food -- is HARD. It is WORK. Get used to it. 

Lean muscle doesn't just "come naturally" to them. They aren't "lucky" to have six-pack abs and sleek curves. Regular, vigorous exercise and mindful restraint at the table is a lifestyle for them, not a rare occasion. 

Understand, these are people who order plain grilled chicken, broccoli and water at a Tex-Mex restaurant. THAT is commitment. How do they do it?

Across the board, all of these shiny people succeed because they know what they DO want, more than the cheese enchiladas, the slushy margaritas, the big crunchy baskets of chips. And they're learned to keep those goals top of mind, even on Saturday night at Mi Cocina. 

(The money managers I know say similar things about maintaining financial health. Remember Your Priorities.)