According to the Australia Dietary Guidelines, flavoured milk is classified as a Five Food Group food. Although flavoured milk can contain added sugar, it also contains all the same nutrients and health benefits of plain milk.

Soft drink is classified as a discretionary (or junk) beverage in the Australian Dietary Guidelines, meaning we should limit our intake. This is because it’s high in energy and low in essential nutrients.

On the other hand, all types of milk, including flavoured milk, are considered Five Food Group foods in the Australian Dietary Guidelines. Although flavoured milk can contain added sugar, it contains all the same nutrients and health benefits of plain milk.

Interestingly, children who drink flavoured milk are more likely to meet their daily requirements of key nutrients such as calcium, vitamin A and phosphorous, than those who don't. Evidence also shows flavoured milk does not lead to weight gain or tooth decay. 

Most flavoured milks available in Australia contain no more than 5% added sugar – this means a 250mL serve contains about two to three teaspoons of added sugar. Most of the total sugar in flavoured milk comes naturally from the lactose in milk.

References

Fayet F, Ridges LA, Wright JK, Petocz P. Australian children who drink milk (plain or flavored) have higher milk and micronutrient intakes but similar body mass index to those who do not drink milk. Nutr Res. 2013;33(2):95-102.

Fayet-Moore F. Effect of flavored milk vs plain milk on total milk intake and nutrient provision in children. Nutr Rev. 2015;74(1):1-17.

Murphy MM, Douglass JS, Johnson RK, Spence LA. Drinking flavored or plain milk is positively associated with nutrient intake and is not associated with adverse effects on weight status in US children and adolescents. J Am Diet Assoc. 2008;108(4):631-9.

National Health and Medical Research Council. Australian Dietary Guidelines Canberra: Commonwealth of Australia; 2013.