LOS ANGELES - The percentage of Americans who are dieting is at its lowest in at least 16 years even though most adults say they would like to lose 20 pounds, according to a study released Wednesday.

Baby boomers are making their own dieting decisions rather than relying on medical advice, said Harry Balzer, author of the study by research firm NPD Group.

"This is a time in life where health issues begin to creep into our lives, and in the past, doctors provided advice," said Balzer, NPD vice president.

"It appears people in this age group today are either not getting - or not listening to - their doctor's advice," he added in a statement.

According to the survey, in the 12 months ended in February 2006, 26 percent of women and 19 percent of men in the United States said they were on a diet. That's down from 35 percent of women and 26 percent of men in 1990.

Still, 60 percent of U.S. adults say "they would like to lose 20 pounds," the study said.

In 2006, the most popular diet in the United States was a self-made regimen, the study said. The second-most followed diet was one prescribed by a doctor, and the third was Weight Watchers.

Government health officials estimate about 60 percent of the adult population is overweight, with the number of those considered obese on the rise over the past decade.

A recent survey by the Centers for Disease Control and Prevention found about 23.9 percent of U.S. adults are obese, up from 15.6 percent in 1995 and 19.8 percent in 2000.