CASSANDRA Bright almost halved her body weight, and saved her own life, in 12 months.
The 36-year-old North Shore resident shared her story, and revealed her jaw-dropping transformation, on Nine's hit new show This Time Next Year on Monday night.
At the time of filming in February last year, Ms Bright weighed 180kg and obesity was ruining her life. At the follow-up a year later, also aired last night, she was 100kg and today she is 82.5kg.
The former aged-care worker said the threat of dying young inspired her to turn her life around and "start living, not just existing".
"I was suffering from major depression and anxiety that basically kept me in the house and I was suicidal. I had no choice, I needed to do something drastic, so I decided to have some weight-loss surgery," Ms Bright said.
On the same day as her consultation for gastric bypass surgery she was made aware the new transformation show was looking for people to make life-changing pledges that would be followed up, on camera, the following year.
With the encouragement of her husband, Steve, her "biggest cheerleader", Ms Bright applied online.
"It was a fantastic motivator, I don't know if I would have been as successful as quick if I hadn't have had that," she said.
In the early days Ms Bright's exercise of choice was low-impact aerobic-type movement in the water.
But she was soon going to the gym four times a week and had joined Geelong's Body Positive Hiking Group for plus-sized women, which saw her tackle paddle boarding at 154kg.
Through the group she discovered Adventurethon, a multisport challenge combining kayaking, mountain bike riding and trail running.
"I came to life. I got a sense of adventure," Ms Bright said.
"My first Adventurethon took me 3 hours and 27 minutes. It was a 1km kayak, 11km mountain bike ride - which I did on a Kmart Huffy with only front breaks - and I walked the 6km at the end.
"When I came through the finish line and got my first medal ever I cried my eyes out because I thought "how far have I come"."
The experience sparked an addiction to collecting event medals.
She got swimming lessons and did a triathlon, took up yoga to strengthen her mind and body and discovered a love of trail running.
"I brought gym equipment to put in my craft room, which used to be my hobby, sitting down all day drinking endless cans of soft drink and eating by myself in a room ... now it's my gym," Ms Bright said.
She's completely free of antidepressants for the first time in 15 years.
"My life has done a 360 degree turn. I can see how beautiful the world is and I couldn't see that before," she said.
"On my great days I would never ever know that I suffered from depression. If I feel down I just go and exercise because it gives me that high, that buzz, makes me feel alive."
Ms Bright said she wished she had made the change 10 years ago and hoped by sharing her story she would encourage others to do the same.
"I just hope that other people who are overweight and feel as miserable about themselves as I did to know they can do it," she said.
"They deserve to live as much as I deserve to live.
"I've gone from not wanting to live to loving everyday."