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."
Social Media Provides Audience for Accountability and Support
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.
TweetWhatYouEat Shames Users Into Watching What They Eat
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."
Tweeting Expenses Can Help With Savings
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.
Unlike TweetWhatYouEat, he said, all messages are automatically posted anonymously. Users post messages about each of their expenditures with the goal of tracking -- and hopefully reducing -- their spending.
He added that his newest site includes another interesting feature -- a Wall of Shame. Any entry you're not too proud of -- from an overpriced pair of shoes to an extravagant meal -- can be dragged over the wall for all members of the site to see.
Sajan Parikh, 19, a student in Walcott, Iowa, has been a devoted user of the site for more than a year and said it's helped him figure out where and when to cut back.
At first, it was a hassle to post every transaction. But now, he said, "I have it posted before I even get my change back."
Tweeting, Texting Helps Smokers Quit
Every week or so he goes online and takes stock of his spending, from video games and iPhone apps to Starbucks coffee and McDonald's meals.
"It's made me aware," he said. "It's easier to save when you know where it's going."
Social media is even helping smokers quit the habit.
Launched in March 2008, Tobacco Free Florida's Qwitter relies on Twitter to help users stop smoking.
Every time a user lights up, they send Qwitter a message with the number of cigarettes they smoked that day -- for example: @iquit3. With that message, Qwitter tracks the user's progress on a chart.
A spokeswoman for the Florida Department of Health said the site has about 1,000 members, although she said they are unable to track if someone quits.
"We do note that adoption is high even as a novelty; and even if it gets one person to think about quitting, we have done our job," she said in a statement. "Qwitter should be used as a support system and is encouraged to be used in conjunction with other resources, such as tobaccofreeflorida.com and the Florida Quitline."
A recent study in New Zealand indicated that another form of social media -- text messaging -- could help people stop smoking.
Called Txt2Quit, the program run by The Quit Group, a charitable trust funded by the New Zealand Ministry of Health, sends smokers who are trying to quit personalized text messages of advice and encouragement over 26 weeks.
The year-long program found that using the messages doubled reported quit rates from 13 percent to 28 percent after six weeks.
Dr. John Grohol, a clinical psychologist and founder of the online mental health resource PsychCentral.com, said that though any program is only works when a person can stay committed to it, social media reminds people of their commitments not just to themselves, but to others.
"Social networking allows that person-to-person connection that keeps our motivation alive," he said. "It keeps us not wanting to disappoint other people who have made similar pledges."