The Weight of the Nation: ChoicesThe second film in the series poses a question that almost anyone who's struggled with excess weight has asked, if only in jest: For all the remarkable high-tech tools available to medicine, for all the billions of dollars in drug research, there's still no highly effective medication to prevent or reverse obesity – why?

Researchers are, in fact, developing and evaluating strategies to help people reach and maintain a healthy weight, so that they can look forward to healthier lives. Diet is a part of the equation, but most name-brand diets promise quick, dramatic rewards and gloss over the long-term effort needed to keep weight off. Maintaining weight loss is a challenge, and success requires sustained changes in our food and physical activity.

Weight - whether we gain it or lose it - is dependent on our body’s energy balance: We are in balance when we take in and burn off the same number of calories each day. Take in more calories than we burn, and the pounds add up. Take in fewer, and the number on the scale goes down.

Other episodes: 1. Consequences, 3. Children in Crisis, and 4. Challenges.

Watch the full documentary now