"Sports teams stopped for me and then I was always out with friends and then it's the late-night McDonald's on the way home, it's the vodka cranberries and it's all the sugary foods," she told news.com.au. "Over the years it just took a toll on me."
Hamblin-Walker decided it was time for a change in November 2019 after noticing that not only was she lacking in energy, but she was also starting to feel self-conscious about how she looked.
"I remember I was in a changing room in Big W and I thought oh, are these mirrors right?" she said.
"I was just really shocked. I thought, I've got a lot of cellulite, and I've got muffin top and this wasn't who I was."
Determined to make changes, Hamblin-Walker decided to give the 28 By Sam Wood program a go as "gyms scared me".
To her surprise she found doing the 28-minute exercise programs were not only "so easy" to commit to, but also had the added bonus that she could do them in her living room while watching TV.
Hamblin-Walker also started making small changes to her diet at the same time, eating smaller portions and adding more whole foods to her meals that also kept her fuller for longer.
"I'm not out here eating a lettuce leaf, I'm having food, like real food," she said with a laugh.
"Before I was having fast food and packets of chips in recess groups and starving when I got home and eating lots and lots.
"When I started with the Sam Wood programme it was just eating healthier foods and that was what was keeping me full for longer, while a packet of chips and a Le Snac was just making me hungrier."
Before long her "snacking had completely stopped" and she began to notice her body was changing too.
In six months she went from a size 12 to a size 10 and now weighs 61 kilos – and she still manages to go out and have fun nights with her friends.
"When I go out at night I'll have a vodka soda, I'm not going to have vodka cranberries I'll just have vodka soda, or one glass of red wine," she said.
"If I'm getting a meal I'll make sure it has a salad with it, just something like that.
"But I'm not going to say no to a pizza slice or Korean barbecue, I just make sure I keep my workouts consistent and it's totally fine."
Hamblin-Walker's transformation has also helped her to accept herself and love the body she is in – a message she wants other people who want to lose weight to hear.
"Everybody is beautiful, I'm very careful not to say you need to be thin to be healthy, because that's not true. You can be fit and healthy at any body type," she said.
"But if somebody feels like they want to make the change and they want to become fit and healthier then I would suggest to do something that is fun for them and that is comfortable."
