This morning the Senate Commerce, Science, and Transportation Committee held a hearing on protecting consumers from false or misleading weight loss advertising. Last year Americans spent about $2.4 billion on weight loss products, and according to the Federal Trade Commission, it is the most common source of consumer fraud, with 7.6 million cases in 2011, the most recent year for which numbers were available.

Dr. Mehmet Oz may be the best-known peddler of weight loss scams. When he talks about shedding pounds, his show has attracted more than 3 million viewers. The supplements he hawks have been thoroughly debunked, but this has not stopped audiences from buying them—in part because it can be hard to parse the true, helpful information he offers from the dubious and unscientific. Those who are duped are more likely to be those who can least afford it: A recent study from the University of Delaware shows that poorer women especially rely on television—as opposed to their physicians or even Internet research—for their health information.

Sen. Claire McCaskill chairs the consumer protection subcommittee, and she really takes it to Oz for his irresponsible guff. You can watch him sputter under her withering gaze and pointed questions:

The exchange goes on. Oz continues to try to claim that his endorsements are legitimate, but anyone with a functioning temporal lobe can tell that even he must not believe his words. “The scientific consensus is monolithic in being against you in terms of the efficacy of these products,” McCaskill points out later. “My job on the show, I feel, is to be a cheerleader for the audience” is Oz’s lame response. Remember that if you find yourself in need of a coronary bypass and he's your surgeon.