With the safe and reliable weight-loss combination of diet and exercise, it's difficult to lose more than about a pound within a four-day period of time. However, depending on how much you weigh and the techniques you employ to slim down, it could be possible to lose 3 pounds or more in as many days. No matter how speedy your progress, it's important to realize that quick weight loss does present some serious risks.
According to the National Institutes of Health, a combination of low-calorie eating and regular physical activity can lead to weight loss of 1 to 2 pounds per week, or between 1/2 to 1 pound every four days. Very-low-calorie diets, during which you eat 800 or fewer calories per day, can produce greater weight loss, but require medical supervision to be safe.
The Weight Control Information Network reports that people with obesity who follow such diets may lose up to 5 pounds per week, or about 3 pounds in four days. Other methods may yield different figures. Closely following gastric bypass surgery or another type of weight-loss surgery, for example, a patient may be able to lose closer to 5 pounds in four days.
Weight-loss progress depends on how many calories you are able to consistently burn or save in relation to how many calories you eat. The more calories you burn or save, the quicker you will lose weight. Losing a pound requires burning or saving a total of 3,500 calories, so to lose that much weight in four days, you'd need to create a calorie deficit of 875 calories daily.
One way to create such a calorie deficit is to reduce your daily calories. The National Institutes of Health does not recommend that women eat fewer than 1,200 calories daily or men fewer than 1,500 calories daily, but if you're currently eating quite a bit more than that, lowering to near those amounts could bring quick results.
Exercise is another safe, reliable way to burn calories. A 200-lb. person can burn more than 700 calories per hour with jogging, more than 800 with a stair treadmill and more than 900 with jumping rope. That much exercise could lead to a total weight loss of around 2 pounds or more in four days, especially if you combine it with low-calorie eating.
Losing weight quickly can be risky business. Thrusting yourself into vigorous workouts or dramatically cutting calories are not sustainable long-term methods for weight loss, and they may increase the likelihood that you'll gain back the weight when you return to old habits. Other quick weight-loss methods, such as fad diets or appetite suppressants, could lead to nutrient deficiencies, fatigue, headache or other negative effects. Therefore, it's essential to always talk over a weight-loss plan with your doctor before you begin it.