One pound of fat contains 3,500 calories, so losing 20 lbs. means creating an overall deficit of 70,000 calories. While that number may seem intimidating, you can pick away at it gradually through moderate calorie reduction and exercise.
Safe Weight Loss
The American Council on Exercise suggests a moderate weight loss goal of 1 lb. per week. Following this advice, you can lose 20 lbs. in as many weeks, or approximately four and a half months.
Calories for Weight Management
When you consume fewer calories than your body can burn each day, you begin to lose weight as your body turns to fat stores for energy. To lose 1 lb. of fat each week, you must cut 500 calories each day through diet or exercise. A woman who usually consumes 2,300 calories per day and adds 100 calories worth of exercise each day would need to consume 1,900 calories to lose weight.
Tips for Cutting Calories
Eat four or five smaller meals throughout the day to keep your metabolism active and reduce hunger between meals. Avoid foods containing simple sugars or processed flour, alcohol, butter and fatty meats such as bacon or sausage. Instead, eat a variety of vegetables, fruits, whole grains, low-fat dairy and lean proteins.