For me, I just make sure to eat pretty well 95% of the time. I make sure to get enough protein and not eat too many calories. I rarely eat fruits or vegetables. I've been able to control weigh loss and gain (I lost 35lbs, now I'm trying to gain muscle, I'm up 20lbs, but about half is muscle). I occasionally have a bad day, but it doesn't really hurt me. I eat the things I like, so it's easy to stick with my diet. I get a physical yearly, and have never had problems since I started watching my diet and exercising.