The number of false claims in media advertisements for weight-loss products from diet creams to wraps and patches has dropped significantly under voluntary screening by media outlets, the Federal Trade Commission said in a report released on Monday.

Fifteen percent of ads reviewed in 2004 made one or more clearly false claims compared with 49 percent in 2001, according to an FTC survey of advertisements for nonprescription products.

With Obesity on the rise and consumers spending heavily on weight-loss products and services, the FTC last year appealed to television, radio and print outlets not to run ads containing obviously false claims.

The FTC sued six privately held firms as part of its effort to curb false weight-loss claims but said there were no plans to file complaints against media outlets, which it said help “lend an air of credibility” to products.

The media were asked to reject ads containing statements included on an FTC list of “Red Flag” claims - results that are not scientifically feasible for nonprescription weight-loss products.

Five percent of the ads in the 2004 FTC survey contained the Red Flag claim that users could lose 2 pounds (0.97 kg) or more per week without cutting calories or exercising more. In a 2001 survey, 43 percent of the ads made that assertion, the FTC said.

Although the survey indicated a steep decline in deceptive ad claims, there was much work to be done, the FTC said. But the agency will continue to leave it to media outlets to continue voluntarily weeding out bad ads.

“Good media screening is good business,” FTC Chairman Deborah Platt Majoras said in a statement. “I encourage the media to continue their efforts to identify and reject clearly false-weight-loss advertising.”