An ad for Sensa, which the FTC just forced to pay $26.5 million in refunds.

This morning, with characteristic fanfare, the Federal Trade Commission announced a "crackdown" on the makers of faddish diet products that engage in deceptive advertising: LeanSpa, L'Occitane, HCG Diet Direct and Sensa all settled with the agency for a total of about $30 million. It's just the latest salvo in the long-running war against the seedier side of the weight-loss industry, which promises miraculous results for almost no effort ("Get a gym body without going to the gym!" Sensa proclaimed).

It's unclear whether the regulator has made much progress, though. The diet marketing industry has only grown in recent years, as the agency itself notes: Different estimates using various definitions peg it at anywhere between $20 billion in annual revenue to $60 billion (and even into the hundreds of billions, with gangbusters growth to come). In a time of tighter budgets, the online and do-it-yourself supplement categories have grown, as well, at the expense of more comprehensive services such as Weight Watchers. Meanwhile, the obesity rate has skyrocketed, although it's finally leveling off.

So given the fact that weight-loss companies seem not to be dissuaded by some of them getting busted once in a while, is there a more sustainable way to keep a lid on the lying ads?

Well, the FTC does have the power to require media outlets to make sure they don't run false advertising. Instead, it's asked them to self-regulate, starting with a request back in 2003 that publishers and broadcasters screen their ads for obviously deceptive claims. The industry wasn't happy about that, claiming the expectation infringed on its First Amendment rights and also required an expensive clearance process. According to a 2006 article in the Journal of Law and Health, Good Housekeeping was one of the few publications with a screening department, which cost $2.4 million per year -- more than most magazines' annual profit.

Nonetheless, in 2004, the FTC found that it had made some inroads: The percentage of weight-loss ads with one of the "red flags" it identified in 2003 declined from 50 percent to 15 percent. According to the FTC's Richard Cleland, although the agency hasn't done a comprehensive study since then,  informal monitoring indicates the numbers have stayed about the same -- most publishers and broadcasters exercise some level of discretion over the ads they run.

That might not mean much these days, though. As traditional media have lost control of the advertising market, deceptive claims just keep popping up everywhere else.

"The problem is, and what's changed dramatically compared to 2001, is that there's vastly more unscreened weight-loss advertising out there," Cleland says. "Unscreened" means mostly automated online advertising, through social media, Google text ads and large networks that serve ads on sites that might not have any control over what they display. And then there's just the rampant proliferation of Web sites: While the FTC does what it can to shut down fraudulent Internet marketers, it can start to feel like playing whack-a-mole. Even its updated guidance for media executives doesn't help when companies have a zillion other ways to get their message out. And although Cleland says the agency has had productive conversations with some large Web companies -- which he declined to name -- Google AdSense's "prohibited content" guidelines don't include false advertising in the first place.

Meanwhile, some of the other dubiously useful products don't rely on advertising at all: The embattled multilevel-marketing company Herbalife, for example, relies on its network of distributors to make whatever claims they feel are necessary to move inventory. In that case, the company itself would probably be insulated from false-advertising prosecution. Just to make sure, Herbalife hired the former surgeon general who spoke against the idea of "miracle" weight-loss cures when the FTC started cracking down a decade ago.