Washington ? As an overweight child, Lynn McAfee scanned the ads in her mother’s magazines looking for hope in the before-and-after photos of people made thin by seemingly miraculous products.

“These smiling, thin people used to be fat like me,” said McAfee, 53, an advocate for overweight people. “But all I got out of those boxes and envelopes I bought in my childhood and adolescence was the sinking feeling that becoming thin like those people in the ads was hopeless.”

Many people share her frustration. In a first-of-its-kind study, the Federal Trade Commission found that 55 percent of weight-loss ads make claims that are almost certainly false or misleading.

“There is no miracle pill that will lead to weight loss,” Surgeon General Richard Carmona said at a news conference Tuesday announcing the results. “Achieving and maintaining a healthy weight requires a lifelong commitment to healthful eating and adequate physical activity.”

Carmona said companies should use real weight-loss results in their promotions and that publishers and broadcasters should screen ads they run to ensure they “are based on science and not on wishful thinking.”

About 61 percent of U.S. adults are overweight or obese, Carmona said, and more than two-thirds of all adults are trying to lose weight or keep it off. Consumers spent about $35 billion in 2000 on weight-loss products ranging from books and videos to drugs and diet shakes, the report said.

People who buy these products have an emotional and financial investment, McAfee said. When the products don’t work, it hurts, she said.

“We lose our money. We lose our time. We lose our self-esteem,” said McAfee, of Philadelphia. “Weight-loss fraud is not a victimless crime.”

FTC Chairman Timothy Muris said his agency had increased its efforts against deceptive weight-loss marketing and has prosecuted 93 fraud cases since 1990. He said the FTC would have a public workshop on the problem in November.

Muris said the agency filed charges this month against Bio Lab, a Canadian company based in Laval, Quebec, that sells its “Quick Slim” weight-loss product in the United States. The FTC said the product, which contains a substance taken from apples, does not live up to promotions such as: “Lose up to 2 pounds daily without diet or exercise.”

The company did not immediately return calls seeking comment Tuesday.

In May, the FTC sued the marketers of three electronic exercise belts the AB Energizer, Ab Tronic and Fast Abs, accusing them of making misleading claims. Television ads showed people strapping the gadgets on their waists in search of washboard abs. Court injunctions took most of the ads off the air, and the cases are pending.

The FTC conducted the advertising study with the Partnership for Healthy Weight Management, a coalition that includes scientists, government agencies and legitimate weight-loss companies.