Rodney is one of two subjects who elected to have gastric bypass surgery as a way to lose unwanted weight.

Americans are fat--and getting fatter. Today, more than 60 percent of American adults are overweight, and 30 percent are obese. A major public health crisis, obesity is now responsible for more health problems than smoking. In "Losing It," SCIENTIFIC AMERICAN FRONTIERS follows 10 volunteers--including Alan Alda--as they try to trim their waistlines and improve their health.

Ranging in age from 30 to 66 and aiming to lose from 10 to 150 pounds, our volunteers used a variety of methods--from Weight Watchers to gastric bypass surgery--to help them reach their goals.

Subjects, like Wendy, kept video diaries of their weight loss progress.

For six months, our volunteers kept video diaries of their progress. Researchers prefer weight-loss studies to run for a year or more, so we can't claim that our study is scientific, but by highlighting our volunteers' successes and setbacks it does provide insight into just how hard it can be to shed unwanted pounds.

To meet our participants, learn about the methods they used and find out how they did, click here.