Oat, almond or soy: Which plant-based milk has fewest calories?

Plant-based milk alternatives differ widely in taste, but whether you choose oat, soy, coconut or almond also makes a difference in terms of calories.

For those watching their daily calorie intake, almond or coconut milk are the best options, as they only contain 13 to 21 kilocalories (kcal) per 100 mililitres, according to a German consumer advice centre.

Keep in mind though that this is only true for unsweetened drinks.

Almond and coconut milk also contain less fat than cow's milk.

The fat content of whole milk is 3.5%, with some 65 kcal per 100 millilitres.

Skim milk, which has a fat content of 1.5%, contains some 45 kcal per 100 millilitres.

If you don't drink cow's milk but want to boost your protein intake, soy milk is the way to go, says Germany's Max Rubner Institute, a government research agency that focuses on nutrition.

Soy milk, which contains 38 kcal per 100 millilitres on average, has a better "protein quality" than oat and almond milk, researchers at the institute found, a finding they attributed to the high proportion of essential amino acids in soy milk.

Better protein quality means it's easier for the body to process the protein in soy milk.

Since oat milk is based on grain, it contains lots of carbs and little protein. Oat milk also contains 46 kcal per 100 millilitres, the most of all plant-based milk alternatives examined.

Barista plant-based milks, often used for frothing, tend to contain even more calories and fat, according to the consumer advisers.