In recent years, oat milk has risen from obscurity to become the plant-based milk of choice for many consumers worldwide, and is arguably the milk alternative most commonly offered in cafes and coffee shops.
But over the past year, viral social media posts and tabloid-style news articles have claimed that oat milk is deficient in nutrients, and have blamed the milk alternative for health issues such as bloating and blood sugar spikes. Here, we take a look at some of these claims.
Is oat milk high in sugar?
Many oat milk brands do not contain added sugar, but the way they are produced does allow the natural sugars in oats to be absorbed more rapidly into the bloodstream compared to eating whole oats. However, cow’s milk often contains more sugar than oat milk; for example, Tesco whole milk contains 4.7g of sugar per 100ml, compared to 3.4g per 100ml for Oatly Whole.
Furthermore, some oat milk brands have responded to consumer concerns by launching oat milks that are produced differently to reduce blood sugar spikes; for example, Oatly “No” Sugars contains 0g of sugar.

Is oat milk low in nutrients?
Most oat milks are fortified with nutrients such as calcium, vitamin D, and vitamin B12, often containing equivalent levels to cow’s milk. Oat milk is lower in protein than cow’s milk, with Oatly Whole containing 1g per 100ml compared to 3.5g for Tesco whole milk; however, Oatly nutritionist Ulrika Gunnerud PhD told The Evening Standard that this is often not an issue.
“Whilst oat drinks do typically have lower levels of protein than cow’s milk, for people eating a balanced, varied diet, which fulfils energy needs, insufficient protein intake is not usually an issue, as we are getting more protein than we need,” she said.
For those who want a higher protein content, dairy is not the only option — soy and pea-based milk alternatives are both high in protein.

Does oat milk contain additives?
Some oat milks contain added ingredients such as emulsifiers and vegetable oils, but dietitian and nutritionist Dr. Reema Pillai told The Evening Standard that these are likely not a concern when consumed in moderation. For those who are worried, some oat milks — particularly organic varieties — are additive-free. Pillai also notes that contrary to online claims, oat milk does not usually cause bloating, as its fiber content is relatively low.
A growing market
Despite claims that consumers are turning away from oat milk, the market is predicted to be worth $6.45 billion by 2028, growing with a considerable CAGR of 14.2%. Oatly reported strong financial results for 2023, and companies traditionally focused on animal products are becoming increasingly interested in the sector; for example, Danone has just completed the conversion of a dairy yogurt plant to an oat milk facility.
While some plant-based categories have faced difficulties due to the cost of living crisis, sales of milk alternatives remain strong. For the foreseeable future, it seems unlikely that oat milk is going anywhere.