Eat This, Not That

It can be tricky adding a diet component to a workout program. In fact, you might be feeling hungrier now that you're exercising more. To properly fuel your body while still losing weight, eat three meals and one or two snacks daily. But for each of your meals and snacks, see where you can cut the fat, both literally and figuratively. "Making smarter food choices and swapping good foods for bad is easier than you think," says Kim Lyons, personal trainer from The Biggest Loser and coauthor of Your Body, Your Life (Sterling).

On the days when you exercise less, swap more foods; on days when you exercise a lot, swap fewer foods. "It's tempting to cut a lot of calories every day, but if you do that, your body goes into a sort of shock, hoarding all the calories you eat, and you stop losing weight," says Lyons. To keep progressing safely, try to trim no more than about 500 calories from your diet each day.