Physical activity helps manage weight and is critical in preventing weight gain. If you wish to lose weight, you need to reduce your calories AND increase your energy expenditure. It's very difficult to shed pounds by increasing your physical activity alone! To lose weight and keep it off you should know a few basics:
1. One pound = 3,500 calories. 2. Lose only 1 to 2 pounds each week. Severe calorie restriction slows your metabolism and can cause you to lose muscle rather than fat. And that's not good because in addition to looking more firm than flabby, muscle also burns more calories.
You'll be more successful if you think about reducing calories by about 250 calories a day (or a bag of chips) and increasing energy expenditure by 250 calories (or walking briskly for 2.5 miles), a total of 500 calories a day. In 7 days that's 3,500 calories or one pound!
Overweight or obese people can significantly improve their health by losing 5 to 10 percent of their body weight. For someone who weighs 300 pounds, that's 15 to 30 pounds of weight loss at a rate of 1 to 2 pounds per week.