Narrator: This is Science Today. Laurel Mellin of the University of California, San Francisco works with people who are overweight. Unfortunately, she's not likely to run out of clients.

Mellin: What's so frightening is that in the last ten years, the objectives for the nation were to decrease obesity in adults, and in fact it's increased 31 percent in the last 10 years.

Narrator: Mellin runs a weight-loss program called The Solution. She says getting people to lose weight over the short term is easy.

Mellin: You can help people change from butter to canola oil or even get on a bicycle if they have a personal trainer there to crack the whip, but to really get a long term change in weight is the most difficult change that's physical that we can see.

Narrator: But Mellin says her Solution program addresses the root causes of overeating and inactivity. She says that leads to real long-term weight loss.

Mellin: What we've seen, which is very contradictory to most of the literature on obesity treatment, is that in fact people even two years later are still losing more weight. And they're exercising even more than they did even one year after they received this training.

Narrator: For Science Today, I'm Steve Tokar.