Which Milk Is Highest in Sugar?

If you’ve got milk, you’ve most likely got sugar too – the two pretty much go hand in hand. Aside from unsweetened plant-based milks and specific sugar-free products, pretty much any carton of milk you pick up, whether dairy or non-dairy, will include some amount of natural sugar. And on top of that, many varieties of milk contain a substantial amount of added sugar as well, because brands and manufacturers choose to sweeten them even further.

So, between dairy milk that’s naturally high in sugar and plant-based milk that tends to be loaded up with added sugar…which milk has the highest amount of this sweet stuff? When it comes to naturally occurring sugar, the winner is somewhat surprising and elusive: donkey milk. But when it comes to total sugar content, including added sugar, flavored milk takes the cake. If you’re looking to avoid high or unwanted sugar in your milk, then steer clear of these products.

Milks with the most sugar

Since donkey milk is very high in lactose, it’s also very high in sugar – it can contain up to 16 to 18 grams per one-cup serving. The only other comparable milk in terms of lactose is human breast milk. But since chances are you won’t be stocking your fridge with either donkey or human milk, there are a few other more mainstream products to be aware of that are high in natural sugar. 

Unsweetened rice milk naturally contains 12.7 to 13 grams of sugar per one-cup serving, which is the most natural sugar of any dairy or non-dairy milk that you’ll regularly see on the grocery store shelves. Cow’s milk is a very close second at 11 to 12 grams of sugar per serving. That goes for all types of cow’s milk regardless of its fat content – whole milk, low-fat milk, and skim milk all contain roughly the same amount of sugar. 

While this is certainly high compared to other lower-sugar milks, sweetened milks can contain double this amount. While many plant-based milks can contain a lot of added sugar, flavored milks definitely pack in the most. Between natural and added sugar, chocolate milk and other flavored milks like strawberry tend to clock in at an average of 24 total sugars per serving.

Here’s a list of some of the highest-sugar milks so you can compare.

Type of Milk	Sugar (Per One-Cup Serving)
Chocolate Milk	24 g
Strawberry Milk	24 g
Chocolate Soy Milk	19 g
Donkey Milk	16 – 18 g
Human Milk	17 g
Rice Milk	13 g
Cow’s Milk	12 g

What types of sugar are found in milk?

You’ve seen lactose mentioned in relation to sugar – that’s because lactose is the naturally occurring sugar that’s present in mammal milk. So whether you go for cow’s milk, goat’s milk, or sheep’s milk (or even those rarer finds like buffalo milk and camel milk), you’ll find several grams of sugar in each cup. This is what accounts for the milk’s main carbohydrate content, and also what gives most milk its naturally sweet taste.

Most types of plant-based milk contain natural sugar as well – although typically in smaller amounts than dairy milk. But this sugar comes in different forms than lactose. For example, that highly sweet rice milk contains glucose; soy milk and coconut milk naturally contain sucrose; and oat milk has a naturally occurring sugar called maltose. 

But since a plethora of non-dairy and plant-based milk alternatives are sweetened with additional sugar on top of the sugars they already naturally contain, there are even more types of sugar that you’ll regularly see on the back of milk labels. Non-dairy milks are sweetened with a wide array of ingredients – from the more natural sugars like honey, agave, and coconut sugar, to artificial sweeteners like high-fructose corn syrup, sucralose, and erythritol.