The 50-year-old Australian comedian, who is best known for her role in Kath and Kim, lost over 26kg with the help of weight loss company Jenny Craig and has managed to keep it off for the past two years.
Szubanski told New Idea magazine: "[Being an inspiration to people is] a bit intimidating because I'm a bit of a flake! But I muddle through and hopefully that helps other people to see it is possible.
"It's normal to feel like quitting. There are times when you just can't get motivated. But the point is to not let that feeling sink in.
She continued: "Emotionally tough times are tricky, but eventually you start to realise that eating self-destructively doesn't solve anything. In fact, it will make you feel worse. You just have to take baby steps, be patient with yourself, but also know when to push yourself."
Szubanski recently revealed that she thought she would "shorten [her] life considerably and be wheelchair-bound" before getting in shape.
Since the weight loss, she has said that she loves working out at the beach and thinks that it is "vital" that "people of all shapes and sizes get out and be active".