How do you lose weight?

The most effective method for weight loss is reducing the number of calories you consume while increasing the number of calories you burn through physical activity. To lose 1 pound, you need an expenditure of approximately 3,500 calories. You can achieve this either by cutting back on your food intake, by increasing physical activity, or ideally, by doing both.
For example, if you consume 500 extra calories per day for one week without changing your activity level, you will gain 1 pound in weight (seven days multiplied by 500 calories equals 3,500 calories, or the number of calories resulting in a 1-pound weight gain). Likewise, if you eat 500 fewer calories each day for a week or burn 500 calories per day through exercise for one week, you will lose 1 pound.
Examples of calorie content of some popular foods and beverages include the following:

• one slice of original-style crust pepperoni pizza - 230 calories
• one glass of dry white wine - 160 calories
• one can of cola - 150 calories
• one quarter-pound hamburger with cheese - 500 calories
• one jumbo banana nut muffin - 580 calories

Any activities you do throughout the day are added to your BMR (basal metabolic rate) to determine the total number of calories you burn each day. For example, a 170-pound person who spends 45 minutes walking briskly will burn about 300 calories. The same time spent on housecleaning burns about 200 calories, and mowing the lawn for 45 minutes consumes around 275 calories. For more, please read the Calories Burned During Fitness Activities article.