Richard Fleming is 53 days into the 90 day diet.

"I've dropped about 11kg since I started spending $14 a week on food," he said.

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Richard is constantly being tempted but the key message behind his campaign is keeping him focussed.

"About 1.4 billion people are living on less than $US1.25 a day," he said.

"I couldn't get my head around that, so I did a research to find what did it truly means.

"If I can bring some perspective to the everyday Australians about the challenges faced by extreme poverty, that's what I want to do."

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After throwing in a promising corporate career to work in the slums of Bangladesh, the 26-year-old returned to set himself this challenge.

"A typical breakfast, two standard servings of porridge and I cut some fruit in there."

"On the weeks I'll have eggs to mix it up.

"Every day is a rice dish with some form of lentil mix.

"Dinner sweet potato and broccoli soup."

He is now on a recruitment drive and already 500 people have agreed to take up his five-day challenge in August.

"It's not just a one-off campaign but a way of helping struggling families and pensioners stretch their dollar further," he said.

According to a new study by University of Western Sydney, many families suffering mortgage stress are living on rice to avoid losing the family home.

"The main tip is to buy savings type brands, home brands in supermarkets," he said.

"You can get flour for $1 a kilogram, oats for $1 a kilo, you can get sugar for $1 a kilogram."

Richard said you can make a lot out of basic necessities.

"I got bananas the other day for 50c/kg," he said.

"I got pears and apples for $1/kg.

"You can find really cheap options from your local market which you wouldn't necessarily find in your supermarket."

While Richard continues to ride 20km to work each day and claims he is not feeling lethargic, he is consulting a nutritionist each week.

Dietican Karen Inge said that would be a good idea.

"It doesn't meet the recommended dietary intakes for most of the vitamins and minerals," she said.

"In the short term, a lack of energy and you'll lose weight."

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So far Richard's "Below the line" campaign has raised almost $30,000 which will be invested into schools.

For details on how to take part in the challenge, visit www.livebelowtheline.com .