Is oat milk healthy? What to check on the carton

Oat milk can be a healthy choice if it is unsweetened and fortified, and if you get your protein from elsewhere. The NHS counts unsweetened, calcium-fortified plant drinks, including those made from oats, as part of the dairy and alternatives food group. The British Heart Foundation notes that it is low in saturated fat and similar in calories to skimmed milk. It also has far less protein than cow's milk, and it does not always contain the nutrients milk is relied on for.

Where it does well

Saturated fat is the clearest win. The BHF table on this page shows 0.2g per 100ml for unsweetened oat drink against 2.2g for full-fat cow's milk. If you are swapping from whole milk, that is a real change, particularly for anyone who gets through a lot of it in tea and on cereal. Calories look similar to skimmed milk: 45kcal per 100ml against 35kcal, and well under whole milk's 66kcal.

That advantage shrinks if you compare it with skimmed or semi-skimmed milk, and some brands add vegetable oils, so fat content varies. Look at your own carton and not at a general table.

The protein gap

The BHF says oat drinks usually contain only around 1g of protein per 200ml, compared with 7g in cow's milk. That is the difference people tend not to notice, because the drink looks and pours the same.

It matters little if you splash some in your coffee and eat plenty of protein elsewhere. It matters more if a big glass of milk or a bowl of cereal was doing much of the protein work at breakfast, for you or your children. Porridge shows this neatly. The BHF puts 40g of oats at 4.7g of protein, rising to 14g with 250ml of semi-skimmed milk. Swap in an oat drink and most of that increase goes. Nuts, seeds or yoghurt on top can bring some back, as covered in our article on porridge.

Calcium: check it has been added

The BHF says oat milk does not naturally contain calcium, so it is usually added. The British Dietetic Association gives 120mg to 190mg per 100ml for fortified plant drinks and warns that unfortified ones do not contain a noticeable amount. So look for calcium in the ingredients and on the nutrition panel.

What does that come to? At 120mg per 100ml, a 200ml glass supplies 240mg, about a third of the 700mg a day the NHS gives for adults. The BDA gives a higher figure of 1,200mg for women after the menopause and men over 55, so if that applies to you it is worth raising with your GP or pharmacist.

Iodine: the one people miss

The BDA says a 200ml portion of cow's milk provides 50 to 100 micrograms of iodine, and that while some plant drinks are now fortified, not all are. It advises checking the label. The BHF notes that the UK's Scientific Advisory Committee on Nutrition recommends fortified plant drinks with calcium, vitamin B12 and iodine, to match the key nutrients in cow's milk.

The BDA adds that vegetarians and vegans, who have few plant sources of iodine, are at risk of deficiency, and suggests seeing a dietitian if you are concerned. If you have dropped dairy altogether, this is worth more of your attention than the choice between brands. The same goes for vitamin B12, which is usually added to oat drinks, though at a lower level per 100ml than cow's milk has in the BHF's table.

Is the sugar a concern?

Oats are high in starch and not sugar, but the BHF explains that processing breaks that starch down into free sugars. So even an unsweetened oat drink contains a small amount, listed at 2.5g per 100ml. Cow's milk shows a larger number, 5.0g, but those sugars are naturally present in milk and the NHS does not count them as free sugars. Comparing the two lines directly is therefore a little misleading.

Sweetened versions are the bigger issue, at 5.0g per 100ml and about 60kcal, which the BHF says can match whole milk on energy. The word "unsweetened" on the front of the carton is the simple filter. Flavoured drinks vary, so check those on their own terms.

For scale, the adult limit for free sugars is 30g a day. Our guide to reading labels on cereal explains how the same sugar thresholds work on food packs, though the NHS notes that drinks use different criteria.

Will it lower my cholesterol?

On its own, probably not by much. Oat drinks do contain beta-glucan, but the BHF says most have only 0.5g to 1g per 250ml, so you would need around 3 to 6 glasses to reach the 3g a day linked with lower cholesterol. It describes oat milk as a helpful swap if it replaces a higher-fat milk, but "not usually enough on its own", and says whole oats are more effective. There is more on the dose in our article on oats and cholesterol.

Giving it to children

The rules differ by age, and this is one place where it is worth following them closely.

Under 1

The NHS says babies under 1 should not have drinks referred to as "milk" that are made from things like rice, oats or almonds.

From age 1

The NHS says unsweetened, calcium-fortified alternatives such as soya, oat or almond drinks can be given, as part of a healthy, balanced diet.

Rice drinks, under 5

Not oat, but easily confused on the shelf. The NHS says under-5s should not have rice drinks because of the levels of arsenic in them.

A child with a milk allergy or intolerance should have the choice of drink discussed with a health visitor or GP, who can advise on suitable options. Given the protein gap, a young child who drinks a lot of oat drink in place of milk needs that protein from other foods, and it is reasonable to ask about that too.

What to look for, in order

Unsweetened on the front. Calcium, vitamin B12 and iodine in the ingredients. Then fat and saturates per 100ml, as these vary with added oils. If it passes those, buy the one you like the taste of, because you are more likely to keep using it.

This article is general information and is not medical advice. Guidance changes, so check the linked sources for the current figures. Last reviewed 27 October 2026.