Nutritionists say that McDonald's new Favourites Combo meal contains almost the entire daily recommended calorie and fat intake.
It contains 1623 calories and 68.5g of fat.
Tania Ferraretto, a dietician for 17 years, said she would never recommend anyone eat the calorific meal.
She said a person's required calorie intake was variable depending on age, gender and activity level but that the average adult needed about 2000 calories per day.
"This McDonald's meal is a huge proportion of that," News.com.au quoted her as saying.
The meal is also dangerously high in saturated fat containing a whopping 24.4g.
"That's more saturated fat in one meal than you need in one day.
"I think it's completely irresponsible and ridiculous to promote a meal like this, especially in the current climate with obesity being such a problem," she said.
McDonald's Hindley St store manager Yihong Hu said the Favourites Combo promotion was proving to be popular.
"Over lunch we have lots of people come in to buy it because it's good value," said Hu of the meal that is only available between midday and 3pm and costs 9.95 dollars.