But in a non-sitting week, the number of people drops to less than half which makes planning a challenge, especially when it comes to minimising food wastage.

The Department of Parliamentary Services changed the way it thought in an effort to tackle the fight on food waste. It was as simple as changing a letter: from "waste" to "taste" and "stale" to "style".

In 2017, the department partnered with OzHarvest to help reduce food waste. OzHarvest collects excess food from Parliament House most Fridays for distribution to those in need.

According to OzHarvest, food waste in Australia costs an estimated $20 billion dollars a year in commercial and residential waste and more than 5.3 million tonnes of food ends up as landfill each year.

In support of the work of OzHarvest, a department spokeswoman said it would demonstrate the belief that "surplus" was just a few letter way from "superb".

Parliament's executive chef, David Learmonth, will cater for guest on Monday at an OzHarvest's event that will have canapes made by using ingredients from parliament that might have otherwise ended up in the bin.

"We have our highs and lows and in terms of our volumes of food wastage," Mr Learmonth said.

"Sometimes when we’ve catered for an event where we didn’t have full attendance or for example they don’t eat as much, any of that left over we sort of try and turn it into reusable waste where we will actually try and contribute to OzHarvest."

OzHarvest launched its campaign to fight food waste earlier this month and on Monday it will screen a documentary, Food Fighter, at Parliament House.

Mr Learmonth said food served include grilled cheese sandwiches with ketchup chutney made from over-ripe tomatoes and leftover cheese collected from buffet and function platters. Chicken leek mornay with fried polenta would be made from leftover pie production mix and filling, and the polenta from excess dry goods close to expiration.

Excess seeds, nuts and grains that have been removed from packaging and close to expiration would be turned into protein bliss bites.

"I think for us, working in this building where the government sits,  you know we really like to encourage and build a more suitable waste free environment," he said.

Parliament House also has bee hives to raise awareness of the decline in the local bee populations, solar panels , and uses biodegradable takeaway cutlery and plates.

OzHarvest aims to target the biggest culprits in its Fight Food Waste campaign and hopes to inspire people to reduce the mountain of food waste at home.