I tend to blow hot and cold on the subject weight-loss TV — hate NBC's "The Biggest Loser," but will admit to having  wept through more than one episode of the Style Network's "Too Fat for 15" — mostly because I know just how unentertaining healthy weight loss can be.

I get it: No one's ever going to launch a prime-time hit with a picture of someone eating smaller portions and exercising in moderation. And you're never going to hear one of those screaming trainers admit that throwing up on the treadmill isn't a strategy for long-term success.

TV wants dramatic stories, and TLC has one, as tonight at 9 it launches a four-part series, "My 600-lb Life," with Melissa, a Texas woman who weighed more than 600 pounds before undergoing gastric-bypass surgery more than seven years ago.

Unflinching in its honesty — even the not-so-squeamish will want to heed those onscreen warnings about the surgery shots, and there are multiple surgeries involved — the episode follows its remarkable subject for not seven weeks, or even seven months, but for seven years.

In seven years, you can tell a story that's much more than a big reveal, and this one, which shows a marriage undergoing changes every bit as drastic as the changes in Melissa's body, is probably must viewing for anyone who thinks a gastric bypass is the easy way out for the overweight.

Or, for that matter, for anyone who thinks all of life's problems can be solved by the right diet.