26/02/2016 6:59 AM AEDT | Updated 15/07/2016 12:51 PM AEST

Career, Health, Confidence: The Personal Effects Of Obesity

Ozgur Donmaz via Getty Images
Obese woman on chair, rear view

For the one in five Australians who are obese, it doesn't feel like a national problem.

It's a problem for their painful joints. It's a problem for their self esteem when when they pick the kids up from school. It's a problem for their career. A problem for their relationships.

For Melbourne woman Miranda Murphy, 48, it's an intimate problem she knows all too well.

She told The Huffington Post Australia she'd been in the unhealthy weight range "for as long as I can remember".

"You read the statistics about how obese people are less likely to get a promotion, or to further their career and you think it doesn't really apply to you," Murphy told HuffPost Australia.

"I come from country NSW and everyone's a bit fat out there -- I didn't stand out -- but when I moved to Melbourne to work in HR, I straight away felt a bit picked on.

"It's like some people look at you and think you can't handle responsibility because they think you can't look after yourself.

"Then you're the one who feels like you're not worth it."

Statistically speaking, weight has a tangible effect on workplace and education -- overweight people tend to be less educated, with 69 percent of adults who left school in Year 11 being overweight compared to 55 percent of university degree holders.

Overweight and obese people earn less, with multiple Australian studies linking obesity to a low socioeconomic status.

An Australian study of blue-collar shift workers also showed overweight workers were significantly less productive, with higher rates of absenteeism and a lower self-reported quality of life.

Priority Research Centre for Physical Activity and Nutrition deputy director Philip Morgan told HuffPost Australia the study was part of research for a men's weight loss program called Workplace POWER, standing for 'Preventing Obesity Without Eating like a Rabbit'.

"It highlighted the well-established psychological and physiological health consequences of being obese -- at a 'societal public health problem'-level but also looking at the individual costs," Morgan said.

Morgan's team ran randomised control trials of steel workers, where some were put on a sustainable weight loss program, while others weren't and the results spoke for themselves.

"There was such a statistically significant difference between productivity between the groups that, from a fiscal business point of view, it's a worthwhile return on investment to give employees the means to be healthy."

Outside of the workplace, excess weight is a major risk factor for Type 2 diabetes, cardiovascular disease and some cancers.

At the start of the decade, obesity overtook smoking as the leading cause of premature death in Australia.

It's statistics like this that keep Murphy awake at night.

"I've got a genetic (predisposition) for Type 2 diabetes, and I know my weight isn't helping. It's those hours after dinner where you're on your own thinking about the future that I get the guilts," she said.

"I don't think I'll ever become a mum. I don't think I'll ever be a normal, healthy weight. Every year I think it's going to be the year I get diabetes.

"My weight literally affects every part of my future. Every part of me."