For example, a person weighing 300 pounds (136 kg) may lose 10 pounds (4.5 kg) after reducing their daily intake by 1,000 calories and increasing physical activity for 2 weeks.

You don’t have to slim down to your high school size to get real health benefits. Losing just a few pounds makes a big difference. Five percent of your body weight — 10 pounds for a 200-pound person — can improve all kinds of health problems, and make you feel better, too.

While losing 10 pounds (4.5 kg) in a week is technically possible, it is not recommended. Short-term, intense eating plans are considered crash diets — meaning that your weight is likely to rebound after you finish the program.

Over the long term, it’s smart to aim for losing 1 to 2 pounds (0.5 to 1 kilogram) a week. Generally to lose 1 to 2 pounds a week, you need to burn 500 to 1,000 calories more than you consume each day, through a lower calorie diet and regular physical activity.

Simply put, you can lose 20 pounds in several months by eating fewer calories than you do now and exercising vigorously for three to five hours per week using resistance training, interval training, and cardio training.

Because a water fast restricts calories, you will lose a lot of weight quickly. In fact, research shows that you may lose up to 2 pounds (0.9 kg) each day of a 24- to 72-hour water fast ( 7 ). Unfortunately, a lot of the weight you lose may come from water, carbs, and even muscle mass.

While factors such as age, gender, and activity level can cause caloric needs to vary, a 1,500-calorie intake is typically less than the average person requires. As a result, this diet may help some people lose weight.