According to the Mayo Clinic, 1 pound equals 3.500 calories. Therefore, a person who wants to lose 2 pounds in one week must burn 7,000 calories more than he consumes during that time period.
Creating a daily calorie deficit allows the body to burn more calories than it consumes and makes weight loss possible, according to ACE Fitness. Calorie deficits force the body to use non-food sources of energy, and the body generally taps into its fat stores to get the energy it needs. A person who consumes 2,000 calories per day and burns off 3,000 calories per day through physical activity creates a daily calorie deficit of 1,000, which is 7,000 calories per week, or 2 pounds.
All calories are either stored as fat inside the body or converted into physical energy, according to the Mayo Clinic. Unless it is burned off, the excess fat that develops due to the consumption of excessive calories will continue to build. The Mayo Clinic suggests using a calorie counter to track the number of calories consumed, avoiding high-calorie, low-nutrient foods, and increasing physical activity to achieve and maintain a healthy weight. It is also important to consult a physician before starting a weight loss program.