In any one meal, Gary Bacon II used to consume potentially 1,800 calories worth of food.
After a cheeseburger, a large order of fries and a soda at his favorite fast food chain, Five Guys Burgers and Fries, Bacon already would be over his recommended calorie intake for a day.
But in 19 days, Bacon lost 15 pounds, sticking to a diet of moderate 300-calorie meals.
"[I tweet] 2-3 times a day everything I eat," the Jacksonville, Fla. 25-year-old said. "It's really helped me to stay motivated."
Bacon is just one of many turning to Twitter to shed pounds, quit smoking or reduce spending. Like digital confessionals, Twitter, Facebook and other forms of social media are helping people find the motivation -- be it from shame, support or accountability -- to overcome vices and change their habits.
"I definitely think there's a trend toward people sharing what they eat, exercise and their vices on social media sites," said Adam Ostrow, editor in chief of the popular social media blog Mashable.
Ostrow said sharing their habits with others, through Twitter, Facebook or blogs, helps people feel accountable and it also helps them feel supported as they try to break bad habits or change lifestyles.
Bacon, as a Web developer and designer, said he spends most of his time sitting at his computer. His desk-bound profession compounded with daily trips out for meals led to an ever-thickening waistline, he said.
"One day, I stood on the scale and I just went, 'Wow! This can't keep going up,'" Bacon said.
He started keeping friends and family updated on a blog -- GetGaryFit.com -- and then started feeding his updates to his Twitter page so that he could share his progress with his hundreds of followers, too.
As Bacon posts his daily meals and their caloric values on his journey from 170 pounds to 140, family members and friends send messages of support and advice.
"Having that kind of feedback and support -- and that instant support from friends -- keeps me going," he said.
In an effort to lose weight before his own wedding, Alex Ressi, 33, launched TweetWhatYouEat.com in January 2008.
Unable to find a simple way to keep a food diary online, the New York-based developer created his own site that lets people keep a Twitter-based food diary by sending messages via mobile text or the Web.
Although people can choose to keep their messages private, by default the TweetWhatYouEat Web site broadcasts, in real-time, members' messages about their meals and caloric intake. Now, the site has about 12,000 members, some of whom have lost 40 pounds, he said.
Ressi said the goal was to make users more aware of what they're putting in their body. But he acknowledged that another force is also behind the site's effectiveness: Shame.
"There is that component of shame," he said. "Perhaps if your food diary is open and public, it may affect what you eat."
Finding success with TweetWhatYouEat, Ressie in October 2008 launched its sister site, TweetWhatYouSpend.
Living in cash-sapping New York City, Ressi said the site was designed to help him figure out where all the money was going.
"This came out from just going to the ATM and taking $200 out and being like, 'What just happened to my money?!'", he said.