How Fast Can I Lose 20 Lbs?

Carrying extra weight is usually the result of a lifestyle of consistently taking in more calories than your body uses on a daily basis. Caloric intake and expenditure is a balancing act — you can exercise regularly and still be overweight if you consume more calories than you need for your level of activity. Gaining an extra 20 lbs. or more doesn’t happen overnight, and likewise, healthy weight loss takes time — especially if your goal is to keep it off.

Weight Loss Basics

Your current body weight is the product of the amount of calories you consume and your activity level. If you’re a steady 20 lbs. overweight, you are consuming the number of calories your body requires to maintain that weight. A pound of fat is equal to about 3,500 calories. To lose 1 lb., you need to cut 3,500 calories from your current diet, burn 3,500 calories beyond what you consume or a combination of both. If you cut or burn 230 calories beyond what your body uses in a day, you’ll lose about 2 lbs. in a month. Similarly, if you consume 230 calories more than you need each day, you’ll gain about 2 lbs. per month.

Safe Weight Loss Rate

Most fitness professionals and health experts consider a maximal weight loss of 2 lbs. per week to be a healthy, sustainable rate. When you lose a lot of weight in a short period of time, you’re more likely to experience a loss of fluid and lean tissue, because it’s difficult for your body to burn a high number of fat calories in a short period of time. Further, the high number of calories you need to cut or burn to produce rapid weight loss is more difficult to sustain, which is one reason why those who lose weight too quickly are more likely to regain it later.

Weight Loss Methods

If you choose to employ a single method of weight loss, reducing your caloric intake is a more effective way to drop unwanted pounds than exercise. Combining exercise with calorie reduction, however, gives you an advantage. You don’t have to severely limit your calories, and your body derives numerous health benefits from regular physical activity, including increased energy levels, decreased risk of chronic conditions and a greater likelihood of maintaining a healthy weight long term. The process of limiting caloric intake is the same for everyone, while the number of calories you burn through exercise depends on your body weight, the activity, its duration and your level of intensity.

Considerations

To lose 20 lbs. at a rate of 2 lbs. per week, you must cut or burn 7,000 calories more than you need each week to maintain your current weight, or 1,000 calories per day. If you weigh 170 lbs., for example, you can burn just under 400 calories by walking four miles in one hour. You can cut the additional 600 calories from your diet by reducing portion sizes or eliminating sugary drinks and processed foods, depending on the types and quantity of food you eat. In the first two weeks, you may drop 6 to 10 lbs. as your metabolism adjusts. At this rate, you can expect to lose 20 lbs. in seven to 10 weeks.