Thanks to NBC’s “Biggest Loser,” weight loss has became a spectator sport. The season two finale aired Tuesday, occupying two hours of prime airtime. This program has been a runaway success, presumably finding a ready audience in the countless Americans who funnel billions of dollars annually into the diet industry.

It has been suggested that the 25 percent of Americans who are obese face discrimination that is subtle and widespread. The self-defeating nature of the diet business contributes to feelings of hopelessness among those seeking to lose weight, and against this backdrop, NBC’s “Biggest Loser” is — dare I say it — surprisingly refreshing.

Like many others, I am generally suspicious of businesses selling weight-loss techniques. Because such ventures depend upon overweight people to fuel profits, they face a not-so-subtle conflict of interest: Any technique that legitimately helps people drop pounds in a sustainable manner will cannibalize its own client base in quite short order. Selling diets is an awfully short-lived business if the product actually works.

Granted, it is hardly challenging to criticize “Biggest Loser.” After all, this is a show that takes morbidly obese Americans, crams them into spandex, then films them groaning through workouts and panting their way up shallow hills. Millions tune in to watch fat people struggle, weep, burst their Lycra and squabble for money. If life in America is a game of status-display one-upsmanship, and the fat are the silent underclass, then “Biggest Loser” is schadenfreude at its absolute finest.

No discussion of this series would be complete without at least a cursory look at some of the more absurd fallacies it presents. Consider, for instance, the notion that to effectively weigh fat people you need a scale the size of a vehicle, complete with flat-panel LCD monitors. Or that, to increase user suspense, these precision instruments deliberately display a series of incorrect values for several seconds before revealing the true measurement. (NBC should market such scales to scientists, who might welcome such excitement at the weigh station.) Perhaps worst of all is the subtle overstatement of the rewards of slimming down. For most people, losing 50 pounds is a remarkable and health-enhancing achievement, but doing so does not conjure $100,000 into your checking account or draw everyone you’ve met from middle school onward to stand cheering on your driveway.

But the simple fact is that the contestants on this program lost a truly astonishing amount of weight. Finalists Seth, Suzy and winner Matt went from bulbous heavyweights to razor-thin, cut-and-pumped hotties right before our eyes. Admittedly, they were chasing a quarter of a million dollars under the constant harassment of personal trainers and with TV cameras thrust in their faces. Say what you will; they’re all now amazingly thin.

Against all odds — despite the teary eliminations, the manufactured drama, the hammed-up emotion and relentless product placement — “Biggest Loser” was fascinating, for the simple reason that it showed in plain view the astounding elasticity of the human body.

Of course, this doesn’t concern NBC in the slightest. But ratings most certainly do, and this week’s finale garnered the network a home run Tuesday night, beating the rest of the competition by a wide margin. As a result, NBC is already hard at work casting season three, and plans to launch a spin-off series in early 2006. And true to form, they are profiteering at a giddy pace, releasing the “Biggest Loser Workout” DVD and book (featuring cast members) this holiday season. They have even gone so far as to milk money from their audience, launching an online pay-as-you-go support group for those hoping to mimic the success of the contestants.

Still, the national fascination with obesity is not translating to actual slimming. Last month, news wires carried a story about a supposed revolt against the health craze in America, with fast food chains unveiling newer, fattier meals and posting record profits nationwide. Indeed, I wonder how long “Biggest Loser” itself can persist, with its opening credits touting the need for willpower in the face of temptation. Here NBC producers should be careful what they wish for, since a sudden bout of self-discipline might cause audiences not only to lose weight, but to halt their frenzied consumption of products pushed by the network’s advertisers.

“Biggest Loser” is sure to ignite debate, and the show’s many humorous aspects definitely invite a roast. But these should not obscure the fact that the transformations achieved by the top contestants through eight months of diet and exercise are nothing short of remarkable. And if this causes just one person to abandon that exhausting and costly cocktail of self-propagating literature, weight-loss groups and overpriced diet aids, the show will have served an unexpected and valuable purpose.

Michael Seringhaus is a fifth-year graduate student in molecular biophysics and biochemistry. His column appears on alternate Thursdays.