Australians are aiming for more vegetables and smaller portions on their plate, new research from the country's peak body for dieticians has found.

A survey of more than 1,200 people was commissioned by the Dieticians Association of Australia.

It found more than half of Australian adults want to lose weight, one-in-three want to boost their vegetable intake, and a quarter are aiming to reduce portion sizes.

Healthy Weight Week kicks off today, and dieticians have urged people to cook at home more.

Dieticians Association of Australia spokeswoman Professor Clare Collins urged people who wanted to lose weight to steer clear of takeaway meals and cook at home more often.

"If you're looking to lose weight, cooking at home is a really key strategy," she said.

"When you get in the kitchen and start cooking, it means you've bought healthier ingredients and you automatically improve your nutrient intake."

Professor Collins said it was encouraging to see Australians' attitudes to healthy food changing.

"It's very exciting that Australians are actually starting to think about how they might eat healthier and what they need to do," she said.

"What Australia's Healthy Weight Week is trying to do is give them those skills."

Australia's obesity problem a 'national tragedy'

The 2014-15 National Health Survey found 63.4 per cent of Australian adults are now overweight or obese, slightly up on the 62.8 per cent recorded in last survey in 2011-12.

Professor Collins said Australia's weight and obesity issues are a "national tragedy".

"It's a trend we've seen for a long time, and that's why we feel there's a need to focus on healthy eating to help people get to a healthier weight," she said.

"We're up there in the countries that have a very high prevalence of overweight and obesity — this is a national tragedy.

"But, we're trying to do something about it in Healthy Weight Week, by focusing on getting back into the kitchen, get cooking, to eat healthier."