Try to do at least 30 minutes of moderate-intensity aerobic exercise, such as a fast walk or a low-impact aerobic class, five days a week. Additionally, you want to work out all the major muscle groups with strength-training exercises, such as lifting weights or using a resistance band, for 30 minutes two days a week. As you lose weight and your fitness level improves, you may want to increase your exercise to up to 60 minutes a day to burn more calories, but with your doctor's permission and supervision.
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.