Your body weight is controlled by the number of calories you eat and the number of calories you use each day. To lose weight you need to take in fewer calories than you use. You can do this by creating and following a plan for healthy eating and a plan for regular physical activity.

You may also choose to follow a formal weight-loss program that can help you make lifelong changes in your eating and physical activity habits. See below for more information on weight-loss programs.

Calories needed to maintain weight

• about 1,600 calories a day for inactive women

• about 2,200 calories a day for inactive men and active women

• about 2,800 calories a day for active men.

There are two different types of weight-loss programs—clinical and non-clinical. Knowing what a good program will offer and what to watch out for may help you choose a weight-loss program that will work for you.

Non-clinical program

What it is: A non-clinical program may be commercially operated, such as a privately owned weight-loss chain. You can follow a non-clinical program on your own by using a book, video, website, or weight-loss product. You can also join others in a support group, worksite program, or community-based program. Non-clinical weight-loss programs may require you to use the program's foods or supplements.

Clinical program

What it is: A clinical program provides services in a health care setting, such as a hospital. One or more licensed health professionals, such as medical doctors, nurses, registered dietitians, and/or psychologists, provide care. A clinical program may or may not be commercially owned.