CSIRO diet the right fit for slimmer Sarah

Sarah Wolter's turning point came when her company ordered new work uniforms and - weighing 158 kilograms - she could not fit the biggest available size.

"That was really humiliating, having to explain to my boss that I couldn't wear the uniform," the 51-year-old Adelaide resident told AAP.

"Over years you name a diet, I'd tried it - possibly twice."

So in late 2015 she turned to the CSIRO's Total Wellbeing diet, hoping to shed between five and 10 kilos.

Two years later, she had dropped 83kg and has stayed around 75kg since.

Ms Wolter is among 10 of the CSIRO program's success stories who have taken on new voluntary roles as motivators for other members.

"It's very daunting, particularly if you've never been a dieter," she said.

"The questions I'm asked over and over are about motivation, how to keep going.

"People absolutely carve themselves up when they have a bad day and binge out, the same as I used to do.

"It's just about being able to say 'hey, we've been there too'."

With weight loss always a topical new year's resolution, the CSIRO program is focusing on motivation and community.

Apart from Ms Wolter and her fellow motivators, the diet program has also launched the Start Strong online quiz to help Australians understand their mindsets around diet.

"Just having that really good start is motivating in itself," said CSIRO research scientist Dr Gilly Hendrie.

She added people wanting to lose weight tended to be more motivated either by exercise or diet.

"That's important for people starting afresh this year - pick something you enjoy to focus on at the beginning," Dr Hendrie said.

"If you're enjoying it, it's a lot easier."

Dr Hendrie said peer support from motivators such as Ms Wolter is invaluable in the program, particularly in the wake of 2020.

"Connecting with your community is so important, particularly at the moment when we've had those restrictions in our lives," she said.

"People are valuing that support more so."

Ms Wolter's message to other program members is that the work is worth it.

"I never in my wildest imagination would have thought I'd be where I was, losing that amount," she said.

"I am now living a life that I never dared dream would even be possible.

"It's a completely different world."