The more you change your diet, the more health benefits you reap. If you’re only looking to lose a few pounds, a couple of this-for-thats might do the trick. But if you want to reverse heart disease—which research shows may be possible at the rigorous end of this diet’s spectrum of choices—you’re looking at big changes. For most programs, though, you have plenty of room between all and nothing. If you indulged yesterday, make more healthful choices today; if you didn’t have time for a run yesterday, make it a must-do today. What matters most is your overall approach—if it’s doable and pleasurable over the long haul, you’ll stick with it for life.