Plain milk contains no added sugar—it only contains naturally occurring lactose, a type of sugar found in milk. On average, plain milk has about 5 grams of lactose per 100mL.

Take a quick look at the back of a carton of milk and you’ll notice the nutrition information panel. If you focus in on the carbohydrate section, you’ll notice a serve or a cup of plain milk contains around 12-15 g of lactose.

This is the inherent sugar naturally found in milk, called lactose, and is different to table sugar, also known as sucrose. Flavoured milks usually contain added sugar in the form of sucrose or other sweeteners, such as stevia.

An analysis of flavoured milks available in Australian supermarkets shows these products contain, on average, one teaspoon of added sugar per 100mL.Your body processes lactose very differently to sucrose, therefore the amount of sugar naturally found in milk isn’t usually a health concern.