Last reviewed: July 2026

Plant milks vs cow's milk: which should you buy?

Soy drink is usually the closest plant alternative to cow's milk for protein. Oat and almond drinks can work well too, but their protein and fortification vary sharply by carton. There is no single winner: choose for allergy, vegan preference, taste, protein needs and whether a product is fortified.

These are four real Dietly labels, not universal category averages. “Sugar” in cow's milk is naturally occurring lactose; the ingredient list is needed to identify added sugar in plant drinks.

Why soy is different from almond and oat

Calling every carton a milk replacement hides the useful distinction. Soy beans contain far more protein than oats or almonds when diluted into a drink. In the selected labels, soy drink provides 3.0 g protein per 100 g, closer to the 4.2 g in 1% cow's milk. The selected almond drink provides 0.5 g and the oat drink 0.4 g.

That does not make oat or almond drinks bad. Protein is only one job in a meal. They may suit a cereal, coffee, allergy need or preference. It does mean they are a poor substitute when milk is doing heavy protein work in a breakfast or a vegetarian diet.

Fortification is the label line that changes the answer

Cow's milk naturally contributes protein, iodine, riboflavin and B12. Plant drinks can be fortified with calcium, vitamin D and B12, but there is no universal recipe. A product that says “plant-based” may contain added calcium, or may not. Shake the carton if instructed, then read the nutrition panel and ingredients.

A 2022 retail analysis found that cow's milk generally supplied more protein and several micronutrients than the plant drinks tested, while soy was the higher-protein plant option. That is a comparison of products, not a command to choose dairy. A fortified soy drink can be a practical choice; an unfortified almond drink is simply a different food with different strengths.

What about sugar and calories?

Do not compare the sugar line without context. Cow's milk contains lactose, not necessarily added sugar. Plant drinks may have no sugar, natural carbohydrate from oats, or added sugar for taste. Unsweetened versions are often an easy default if you do not want sweetness. The oat drink here has 2.0 g sugar per 100 g; the label alone does not tell the whole story without its ingredient list.

Use Dietly's food comparison tool for a pair you actually buy. It keeps quantities per 100 g, which avoids a carton with a larger serving looking better by default.

Choose by the job the drink has to do

• Protein: fortified soy or cow's milk is usually the stronger starting point.
• Low energy: unsweetened almond and some oat drinks can be lighter, but check that this is useful for your overall meal.
• Calcium replacement: choose a fortified product, then check the label.
• Allergy or vegan preference: a plant drink can fit well; plan B12, iodine and protein across the wider diet.

Bottom line

There is no “best plant milk.” Soy is generally the best bet when protein matters. Almond and oat drinks can be excellent for taste and routine, but do not assume they replace milk nutritionally. Choose a product, read its label and make the decision from what it actually provides.

Sources

• Nutritional composition comparison of plant drinks and cow's milk
• 2024 review of protein quality in plant and dairy milks