In order to lose one pound, you will need to burn 3,500 more calories than you consume in a day. If you weigh 150 pounds, then you burn about 1,500 calories per day just by going about your usual business. If you eat 1,000 calories, then you'll need to burn 3,000 additional calories each day to lose one pound.Eat low-calorie foods that fill you up. Your diet should consist primarily of vegetables and lean proteins. Eat lettuce, celery, broccoli, green beans, spinach, and other greens.