(CNN) -- Just like the people they feature, weight-loss shows come in all shapes and sizes.
From competition shows like "The Biggest Loser" and "Dance Your Ass Off," to scripted sitcoms like "Huge" and "Mike and Molly," weight-centric programming has become a staple on the tube.
And with the recent success of serious-minded reality hits like "Teen Mom," producers are applying the formula to their weight-loss shows.
While similar to documentary-style reality shows like the Style Network's "Ruby" and TLC's "One Big Happy Family," two new docu-series are following a different format, providing viewers with a healthy dose of melodrama.
MTV's "I Used To Be Fat," which premiered on December 29, follows overweight teens on their quest to get fit. Each episode features one character's transformations -- from their last few weeks of high school, through their first days at college.
"Heavy," to premiere Monday, employs a similar format, featuring two adults -- ranging from 240 to 630 pounds -- per episode. The A&E show focuses on the mental and physical struggles people face when attempting to make a lifestyle change.
Like any makeover show, people want to see results quickly, just as they do when they're dieting, said Lynette Rice, a senior writer for Entertainment Weekly. Nobody wants to wait 13 weeks to see if the characters are going to succeed, she said.
"It's really interesting to see one person's journey in an hour," said Amy Baily, who produces "I Used To Be Fat." "They undergo a tremendous change -- not just in terms of weight loss, but confidence levels and how they feel about themselves."
This, of course, is different from "Ruby" and "One Big Happy Family," which spend an entire season with the same characters.
While reality competition shows, like ratings juggernaut "The Biggest Loser," feature contestants in a controlled environment, competing to lose weight for cash, documentary reality shows tend to feature characters in their own domain -- their only incentive for losing weight being their own health ... and maybe 15 minutes of fame.
Docu-series provide a "much healthier point of view for folks at home," because people aren't losing an unrealistic amount of weight every week and there's no prize for motivation, Rice said.
Though Rice, among others, agrees these shows are great additions to the lineup, they're not going to win the ratings game, no matter how compelling.
ABC Family's "Huge" was canceled after one season, despite viewers' efforts keep the show on the air. CBS's "Mike and Molly," on the other hand, has done well for the network. The sitcom, which spurred a heated debate about overweight characters on TV one month after its September 20 premiere, had 8.59 million viewers tune in Monday, according to TV by the Numbers.
Even "The Biggest Loser" recently saw a decline in its ratings. Luring in about 11 million viewers, the season 10 finale was down 20 percent from the season nine finale.
The reason? It might be that being overweight is no longer considered verboten, Rice said. It's not scandalous or controversial like teenagers who "decide to keep their children out of wedlock."
"Shows like 'The Biggest Loser' made it OK to be huge on TV," she said. "People standing up there in their jog bras and bike shorts, standing on a scale ... that's brave."
Even Gabriella, the 18-year-old who was featured in the pilot episode of "I Used To Be Fat," said she never hesitated to share her struggle with viewers.
"I'm not on TV because I went out partying," she said. "I changed my life, and I'm hoping to inspire others. ... It was tough at times, but I knew the outcome would be great."
After all, Rice said, "We're all battling the bulge in varying degrees."