Oat Milk vs Almond Milk: Calories, Protein & Sustainability

Oat milk and almond milk are now standard at every Canadian café, and the question “which is healthier” has no clean answer — it depends on what you’re optimizing for. Calorie density, protein content, environmental footprint, and behaviour in coffee all favour different drinks.

Macros side-by-side (1 cup unsweetened)

Oat milk (Oatly Original): ~120 cal, 3 g protein, 16 g carb, 5 g fat, fortified with calcium and B12.

Almond milk (Silk Unsweetened): ~30 cal, 1 g protein, 1 g carb, 2.5 g fat, fortified with calcium and B12.

For calorie-conscious eaters, almond milk is dramatically lower (30 vs 120 cal) for the same volume. For carbs, almond is also far lower (1 vs 16 g).

Protein reality

Neither is a meaningful protein source. Cow’s milk has 8 g per cup; soy milk has 7 g; oat has 3 g; almond has 1 g.

If you’re vegan or lactose-intolerant and rely on milk for protein, soy milk is the only plant milk that matches dairy. Oat and almond milks are fine as additions to coffee or cereal but don’t close a protein gap.

Calcium and B12

Both oat and almond milk are typically fortified with calcium and B12 to match cow’s milk. Check the label — some store-brand or specialty oat milks (e.g., barista blends) skip fortification or use lower amounts.

For children switching from cow’s milk to plant milk, fortification matters more than for adults — calcium and vitamin D are critical for bone development. Soy milk and oat milk are typically more reliably fortified than almond.

Coffee performance

Oat milk is the runaway winner for lattes — the beta-glucan and emulsified fats foam well, don’t curdle in acidic coffee, and produce a mouthfeel close to whole milk. Almost every Canadian specialty café defaults to Oatly Barista Edition.

Almond milk often splits or curdles when added to hot coffee. It’s fine in cold drinks but tricky in hot espresso.

Environmental footprint

Almond milk uses ~371 L of water per litre of finished milk — primarily for almond cultivation in California. Oat milk uses ~48 L of water per litre. Cow’s milk uses ~628 L (Poore & Nemecek, Science 2018).

For freshwater scarcity (a real concern in California), oat milk is significantly lighter. For greenhouse gas emissions, both plant milks beat cow’s milk by 4–5×.

The bottom line

Pick almond milk if you’re calorie-conscious or low-carb. Pick oat milk if you’re a coffee drinker or want a richer mouthfeel. Pick soy milk if you need plant-milk protein at dairy levels. None is uniformly “better”.

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