I can't say nobody warned me: Every pregnancy book on the planet predicted that I'd still be wearing maternity clothes when I took my son home from the hospital. Secretly, I thought I'd at least be able to button my stretched-out jeans. As it turned out, I didn't even try, and that was no biggie: I was too smitten with my baby to care. But a month later—when I was still sporting a sizable inner tube around my middle—I started feeling bad about my bod. Returning to "normal" size may take six-plus months, say experts; with plenty of patience and lots of salads, it took me a bit less. No matter how much you have to lose, you'll do it faster with this research-backed plan.
1. Keep track of calories.
Modestly cutting calories to lose a pound a week is a safe way to budge postpartum pudge, even if you're breastfeeding. Scaling back sensibly won't mess with the amount of milk you make or have an impact on its nutritional value, says Cheryl Lovelady, Ph.D., R.D., professor of nutrition at the University of North Carolina, Greensboro, who studies weight loss in postpartum women. Most women will drop a pound a week on 1,200 to 1,500 calories per day—add 300 to 500 calories if you're nursing. Calculate a customized calorie goal at MyPyramid.gov. (Your result will tell you the calories you need to maintain; to lose about a pound a week, subtract 500.) Not yet available: an app to help you quit buying chocolate.
2. Log everything you eat.
Loads of research shows that a food diary can be a powerful tool. One study in the journal Obesity suggests that you're far more likely to monitor what you eat if you use a digital device to keep track. "An app made all the difference in my getting back into a size 6 after having children," says Linsey Knerl, a mother of five, of Tekamah, Nebraska. "Entering my meals and snacks took all of 30 seconds and kept me aware of what I was eating."
3. Snack smart.
Grazing on more veggies, fruits, low-fat dairy, whole grains, and legumes can help you get the crucial nutrients (calcium, iron, fiber, and protein) you need as a new mom and ensure you won't feel deprived. "When selecting snacks, think 'two food groups' rather than 'treat,'" says Melinda Johnson, R.D., a Phoenix spokeswoman for the American Dietetic Association. Snacks with protein tend to have more staying power, research suggests, so make sure there's some in whatever you're noshing on. A few palate-pleasing ideas: an apple with a slice of low-fat cheese, hummus on whole-grain crackers, yogurt and blueberries, or a bowl of whole-grain, low-sugar cereal with skim milk.
Nursing moms may have to make a special effort to pick nutritious noshes, suggests a study in the Journal of the American Dietetic Association, which found that women who exclusively breastfed their babies ate more grains and desserts (think white rice, cookies, and other starchy foods) than moms who fed their children formula or a combo of formula and breast milk. The study's authors suspect that breastfeeding moms may believe that nursing will counteract the calories they're consuming, but it's not exactly true. Sorry!
4. Cut some corners in the kitchen.
Sitting down to long, leisurely home-cooked meals: not gonna happen. You need no-brainer, no-fuss healthy foods, so stock up on cups of low-fat yogurt, string cheeses, individual pots of hummus or pouches of peanut butter, fruit-and-nut bars, low-cal frozen entrées, and pre-washed and cut vegetables.
5. Dump the junk.
Downing a lot of trans fats (usually found in high-calorie baked goods and fast foods) is linked to lingering baby weight, according to a study in the American Journal of Preventive Medicine. "Trans fats could result in inflammation, which may be one of the causes of weight gain," says Emily Oken, M.D., associate professor of population medicine at Harvard Medical School and the study's lead author. For Kristyn Lewis, a mom in Durham, North Carolina, swearing off processed foods, refined grains, sweets, and alcohol enabled her to drop the 8 pounds that remained after her second daughter was born. "I was shocked to discover that my cravings disappeared after a few days," Lewis says. "I generally don't believe in depriving myself, but I was sick of elastic-waist pants."
6. Hide the remote.
Watching more than two hours of TV daily is associated with retaining significantly more baby fat after giving birth, research shows. "People tend to eat mindlessly when sitting in front of the television," Dr. Oken says. Record your favorite shows and watch them while you're doing something else, like folding a load of laundry or, better yet, walking on a treadmill.
7. Steal some zzz's.
Sleep more, with a baby? Yes, it's possible—and good for your waistline. Moms who got five or fewer hours of sleep a day when their babies were 6 months old were three times more likely to be at least 11 pounds over their pre-pregnancy weight a year after delivery than were those who slept seven hours a day, according to a study in the American Journal of Epidemiology. "If you're tired, you don't have the energy to exercise," Dr. Oken notes. "And sometimes you eat to try to activate yourself." Mindless munching won't give you pep, and your body doesn't need the extra calories. Studies also show that skimping on sleep can throw appetite-regulating hormones out of whack. Joanna Grossman, a mom in Burlington, Vermont, felt better after she moved her daughter into her own room. "We didn't wake up at every little sleep snort," Grossman says. Go to bed right after Baby does, Dr. Oken suggests. Wash your face and brush your teeth after dinner, so you can hop in the sack following that last evening feeding.
8. Hang with the girls.
If you thought for a second that we were talking about your breasts, you really need some time away from your Boppy. Studies show that pairing up with a pal is an effective way to say goodbye to pounds. Take it from Amy Pisano, a mom of two, of New Castle, Pennsylvania, who signed up for a Zumba class with a buddy when they were both trying to shed their pregnancy weight. "Going with a friend made me feel more comfortable, which motivated me," Pisano explains. "I lost 10 pounds over the four-month session and had so much fun that when it ended, I signed up for boot camp class!"