The Australian-born Reid, who now lives in Scotland, says she knew she wanted to lose weight when she saw her "enormous white knickers billowing on the clothesline next to my sister's impossibly teeny" pair but, after maxing out the scale at her local Weight Watchers chapter, it seemed impossible to find the support she needed.
So Reid, who'd always kept a journal, decided to try her hand at blogging.
She took full body photos, blurred out her face, and began what became one of the most internationally popular blogs about weight loss -- now with over 500,000 readers, DietGirl.org.
The readers have given Reid the support she needed to become a big loser -- of weight!
Reid chronicles her five-and-a-half-year journey to half her size in the book, "The Amazing Adventures of Dietgirl" (to read an excerpt, , click here.
She visited The Early Show Monday and shared her story, as well as encouragement to fellow dieters.
What made her turn to blogging?
"At first, the anonymity," Reid told CBS News. "All my friends were skinny, so I didn't want to talk to them about how scary and lonely it is to be fat. They're lovely, but they just wouldn't understand -- they don't know what it feels like to not be able to walk down the street -- it is out of their realm of experience. I had always written my secrets in a diary, but I knew the task ahead called for more than a journal. So I would go online and tell anyone who was listening how much it hurt to be this weight -- and every blog entry started with my exact weight. Readers started to cheer me on when the number went down, and encouraged me to stay with it when the number went up. I'm blogging now about how hard it is to maintain a healthy weight."
Reid told co-anchor Maggie Rodriguez blogging "is kind of like anonymous group therapy, in a way. You get inspired, but you also get practical ideas."
Five Tips from Reid for Diet Blogging
1. Share your statistics
People love numbers. Don't be shy about posting your weight and measurements. Reporting your weekly weigh-ins can help keep you accountable, and it's great showing off your shrinking numbers! Some math-nerd bloggers even post their results in a graph. Readers like being able to see at a glance where you are on your journey and cheer you on.
2. Get involved with the blogging community
Read other blogs and leave comments if someone's words catch your interest. Some online communities like Blog To Lose and SparkPeoplehave free, built-in blogging tools, so it's easy to find friendly bloggers to read and talk to.
3. Keep writing through the tough times
So many bloggers disappear when they fall off the wagon. But that's when you need to write more than ever! Share your setbacks as well as your triumphs. The support and encouragement you'll get from your fellow bloggers will help you get back on track quicker than if you just moped in private. Everyone has tough times, and the more you write about your struggles the more you will learn from them.
4. Have fun with your writing!
You might get bored if you just write about what you ate for breakfast. Be imaginative! Share a new recipe you've tried, write a list of things you want to do when you lose weight, or post pictures from your daily walking route so readers can see your part of the world. In 2005, I live-blogged my wedding in Las Vegas, sending photos from my cell phone to my blog, live from the wedding chapel!
5. Beware of blogger butt
Blogging can be very addictive, so make sure you don't get so wrapped up in your writing that you forget to switch off the computer and get your exercise done!
Favorite diet blogs
1. Lynn's Weigh
Lynn blogs about maintaining her 168 pound weight loss.
2. Escape From Obesity
Another Lyn. This one is from Washington state and wants to lose 110 pounds - she's 55 down, 55 to go!
3. Andrew Is Getting Fit
Diet blogging is not just for the ladies! New Zealander Andrew has lost over 100 pounds and discovered a passion for running.
4. Cranky Fitness
A hilarious blog with useful information for diet and fitness newbies.
5. Limes & Lycopene
An Australian nutritionist gives healthy eating tips and advice that's practical and jargon-free.