McDonald's in Australia has revealed the secrets behind the food menu in their 'Our Food, Your Questions' campaign.

He further explained that sometimes their burgers don't decompose when left out at room temperature in a dry environment because when the food is cooked there isn't enough moisture to support mould growth to break it down, so instead, it simply dries out and the same thing will happen to any other cooked food.
However, Dietitian Susie Burrell said that Macca, McDonald's Australian nickname, has a poor quality overall because it is low in vegetables and it has double the recommended fat content.
Source-ANI