I've been counting calories, watching my fat intake, and just generally trying to make healthier choices. I eat a lot of chicken, vegetables, fruit, fish, and whole grains, and I've done this since the beginning. The only times I stop losing are when I stop paying attention to what I put in my mouth (like I did for the whole summer
) It's absolutely a way of eating that I can maintian for the rest of my life, because I can have treats, I just have to ration them. I generally stick between 1200 and 1400 calories per day, and find I'm not hungry at all on this amount. Basically I think it's trial and error for awhile to find out the calorie level that works best for you. Overall, though, if you're making smart food choices and watching portion sizes, you shouldn't have any problems.
Oh, and exercise makes a huge difference in how quickly you tone up.