A survey of 30 cafes in Canberra by the Heart Foundation found 43 per cent of stores used skim milk in skinny orders and 57 per cent used low fat milk. Another 37 per cent of ACT cafes did not offer skim milk at all.

Nerida Volker, a lecturer in nutrition and dietetics at the University of Canberra and advisor to the study, said many Canberrans did not consider beverages in their daily nutrition intake.

"While coffee itself is not high in kilojoules or fat, the way we drink it often is," she said.

"If you regularly drink a large latte made from full cream milk, it could contain 1100 kilojoules and 13 grams of fat. And this could be contributing to an expanding waistline."

Heart Foundation ACT chief executive Tony Stubbs said obesity was at an alarming rate in the ACT and 63 per cent of adults were overweight or obese.

"When you eat or drink more kilojoules than you need to, fat doesn't just build up around your waist," he said.

"Toxic fat can build up around your vital organs, increasing your risk of heart disease."

Mr Stubbs said he hoped the study, which was conducted by the LiveLighter ACT campaign, would prompt people to rethink their dietary habits and realise there was no industry standard.

"We are not discouraging people from having a coffee but to reconsider how they drink it, with a smaller amount of milk, no sugar, and skim milk," he said.

Mr Stubbs said it was common for most people to have one cup of coffee every day, and some people consumed two or three cups, often large and with full cream milk.

"A large or jumbo coffee contains around 1100 kilojoules so if someone is having two or three a day they are already getting towards a third of their recommended daily intake," he said.

The owner of the Lava Espresso Bar in Weston, Lincoln Fairleigh, said there was no reason why cafes should not be supplying skim milk to customers who preferred a healthier alternative.

"For our perspective, full cream milk is the default as it works better and makes it a creamier product," he said.

"There's a slight difference in the price of skim milk and full-cream milk although it's only a couple of cents more per two litre bottles, so it doesn't affect our margins."

Mr Fairleigh said it was common practice for cafes to charge 50 cents extra for soy coffees as it was more expensive milk.

"We also offer a smaller coffee called a magic, which has the same amount of coffee with less milk so it's healthier and we think it tastes better too," he said.

Mr Stubbs also called on Canberrans to avoid having a piece of cake or a muffin and instead opt for a piece of fruit.