Even if you do meet your goal, it's nearly impossible to keep off the weight over the long term: "The amount of restriction required [to maintain that number] will make you so hungry that you’ll eat everything in sight—it’s survival instinct," Dr. Seltzer says. And since calorie restriction gradually slows your metabolism, your body will be less prepared to burn the foods you binge on, he adds. That could mean gaining more pounds than you lost in the first place.
Don’t let extra hours lounging in bed stand between you and a flatter belly. While getting enough sleep can help boost your metabolic rate, sleeping in may undo any benefit you’d enjoy from catching a few extra winks. One study reveals that late sleepers who snoozed past 10:45 in the morning ate nearly 250 more calories over the course of the day, despite eating half as many fruits and vegetables as their early bird counterparts. Even worse, they chowed down on more salty, sugary, and trans fat-laden fast food than those who woke up earlier. If you happen to head out of the house early, you’re in for an additional metabolic boost; researchers at Northwestern University have found that people exposed to just a short period of early morning sunlight had lower BMIs than their late-waking counterparts.