Guzzling down her 10th can of the day, Melanie Arnold-Stemm knew her drinking habits were wildly out of control.

As well as an obsession with cola, she would drink three bottles of sickly sweet iced coffee and then have three more triple shot coffees from a cafe.

‘I had a serious addiction to soft drink, and coffee as well,’ the 27-year-old reveals.

Melanie says her eating habits weren’t much better – as well as downing up to four litres of soft drink, she would gorge on up to three takeaways a day.

At her heaviest, Melanie weighed 143kg and was a size 24. She was medicated for bipolar 1, and also suffered from anxiety, PTSD and PND.

Trapped in an unhappy marriage, Melanie simply ate what her husband ate.

‘I was not in a great place mentally, I lost faith in myself and I just essentially gave up,’ she explains.

It was only her beautiful daughter, Mia-Bella, now four, who gave Melanie the strength to get through each day.

The turning point came when she left her husband in November 2015.

‘It immediately felt like a tonne of bricks had lifted from my body. Once that emotional weight lifted, the fogginess diminished and I was able to see myself for who I actually was. I knew that if I could lose the mental weight, that I could lose the physical weight too.’

Melanie had already lost 8kg since the beginning of that year by reducing her portion sizes.

But now she completely overhauled her diet using the free recipes on the Healthy Mummy website – swapping takeaways for healthy whole foods, and fizzy drinks for water.

The Gold Coast mum says the hardest aspect of her lifestyle change was giving up soft drink.

‘I quit cold turkey, but it was horrendous. I got really bad withdrawals, [including] the shakes, incredible migraines, blurry vision.

‘For the first few days I was bed bound. It feels like your body is drained of everything because it is the sugar in the soft drink that keeps you going.

‘It was hell. But I knew if I had the strength to get out of a bad marriage, I had the strength to give up soft drink.’

Though many assume healthy eating can be expensive, Melanie does it all on a very tight budget.

‘I only spend $75 a week on food. Sometimes only $60. Generally I only buy three lots of meat per week and bulk recipes up with vegetables. I always meal plan around what ingredients I have already got. But before changing my lifestyle I used to spend $130 per week on food for me and my daughter.’

The inspiring single mum, who works as a make-up artist, began exercising a year after overhauling her diet.

‘It’s only the last eight to 10 months I’ve gotten really into exercise. I love it. I first started doing core workouts like crunches and leg lifts. Now I do yoga, boxing and use an 8kg kettle bell for absolutely everything – squats, floor work, even walking up and down my stairs,’ she says.

‘I’ve gone from feeling hungry, tired and disgusting to feeling full, energised, and actually healthy.’

Not only did the weight fall off, but Melanie began to feel much better mentally too – to the point where she no longer needs her medication.

‘Since my weight loss adventure began, I have been in a healthier state of mind. I will never be rid of bipolar, but I can work with it, and make it a part of me, instead of letting it define me.’

Melanie's top tips for getting in shape on a budget

* Use the free Healthy Mummy recipes available on the website

* Meal plan around what you've already got at home

* Stick rigidly to your shopping list

* Bulk meals up with vegetables

* Exercise at home instead of at the gym

This story first appeared on New Idea