What's Healthier, Soy Milk or Oatmilk?

December 2, 2025 •

3 min read

According to the Plant Based Foods Association, plant-based milk sales have consistently grown, making dairy-free options a staple in many households. But with so many choices, figuring out what's healthier, soy milk or oatmilk, can be confusing.

Quick Summary

This nutritional breakdown analyzes unsweetened soy milk and oatmilk, comparing their protein, fiber, and calorie content to help you select the better option for your health and dietary needs.

Key Points

Protein Content: Soy milk contains significantly more protein than oatmilk, including all nine essential amino acids, making it a complete protein.
Fiber for Heart Health: Oatmilk is higher in soluble fiber, specifically beta-glucans, which is beneficial for lowering cholesterol and supporting heart health.
Carbohydrate and Calorie Differences: Oatmilk is higher in carbohydrates and generally lower in calories than soy milk. For those monitoring carb intake, soy is often a better fit.
Fortification is Key: The nutritional value of both milks largely depends on fortification. Look for brands that add essential vitamins like D, B12, and minerals like calcium.
Consider Allergies: Oatmilk is a safer option for those with soy allergies. Conversely, soy milk is an alternative for people with nut allergies.
Beware of Added Sugars: Always opt for unsweetened versions of either milk to avoid high levels of added sugars, which can negate their health benefits.

Nutritional Showdown: Comparing Soy Milk and Oatmilk

When it comes to plant-based milks, soy milk and oatmilk are two of the most popular choices, each with distinct nutritional profiles and health benefits. Your individual health goals, dietary restrictions, and taste preferences will ultimately determine which one is the healthier choice for you.

Soy Milk: The Protein Powerhouse

Derived from soybeans, soy milk is well-regarded for its high protein content, which is comparable to dairy milk. A single cup of unsweetened soy milk can provide around 7 to 9 grams of protein, a significant amount that helps promote satiety and muscle repair. Unlike most plant-based proteins, soy is a 'complete' protein, meaning it contains all nine essential amino acids.

Soy milk also contains beneficial isoflavones, which are plant-based compounds that have been linked to potential health benefits, such as supporting heart health and reducing cholesterol levels. Research has shown that regularly consuming soy products may help lower LDL ('bad') cholesterol. However, those with soy allergies should avoid it entirely, and some people with thyroid conditions might be advised to limit their intake.

Oatmilk: The Creamy, Fiber-Rich Contender

Oatmilk is made from whole oats and water, resulting in a naturally sweet and creamy beverage. Its rising popularity is often attributed to its delicious taste and texture, which foams well for coffee drinks. Nutritionally, oatmilk's standout feature is its high soluble fiber content, particularly beta-glucans. This type of fiber is known to have heart-protective effects, helping to lower blood cholesterol by binding to bile acids in the gut.

Oatmilk is also typically richer in carbohydrates than soy milk, providing a quick source of energy. While it contains less protein than soy milk, many brands are fortified with essential vitamins and minerals, such as calcium, vitamin D, and B vitamins, making up for some of the nutritional deficiencies compared to cow's milk. It is naturally free from common allergens like nuts and soy, making it a safe choice for many individuals with sensitivities. However, those with Celiac disease should ensure they choose a brand certified as gluten-free to avoid cross-contamination.

Comparing Soy Milk and Oatmilk at a Glance


Feature	Unsweetened Soy Milk	Unsweetened Oatmilk
Calories	Higher (approx. 100 kcal per cup)	Lower (approx. 80 kcal per cup)
Protein	High (approx. 7-9g per cup)	Moderate (approx. 3-4g per cup)
Completeness	Complete protein source	Not a complete protein source
Carbohydrates	Lower (approx. 5g per cup)	Higher (approx. 14g per cup)
Fiber	Lower (approx. 1g per cup)	Higher (approx. 2g per cup)
Omega-3s	Contains polyunsaturated fats	Contains some healthy fats
Heart Health	Can lower LDL cholesterol	Contains beta-glucans for cholesterol reduction
Flavor	Mild, nutty taste	Creamy, naturally sweet
Allergies	Avoid if you have a soy allergy	Free from soy and nuts

Making an Informed Decision

When choosing between soy and oatmilk, consider your primary dietary needs. If your goal is to increase protein intake, especially on a vegan diet, soy milk is the clear winner. Its complete protein profile makes it an easy and efficient way to supplement this vital macronutrient. If you are concerned about cholesterol or want to increase your fiber intake, oatmilk's beta-glucans provide a significant advantage for cardiovascular health. For those watching their carb intake, soy milk is the lower-carb option, though oatmilk can be a great energy source. Both are excellent lactose-free alternatives to dairy, but always opt for unsweetened versions to avoid unnecessary added sugars. You can explore the full nutritional breakdowns of various plant-based milks to find the perfect fit for your needs.

The Takeaway: It's All About Your Needs

Ultimately, neither soy milk nor oatmilk is universally healthier; the best choice depends on your specific health goals. For a protein boost and potential heart benefits via isoflavones, soy milk is a superb option. For a creamy texture, heart-healthy fiber, and a soy/nut-free profile, oatmilk is ideal. Both offer valuable nutritional benefits, particularly when fortified, and are significantly more sustainable than traditional dairy milk. By considering your personal dietary needs and health priorities, you can confidently choose the best plant-based milk for your lifestyle.

Frequently Asked Questions

For building muscle, soy milk is the superior choice. It contains a higher amount of protein per serving and is a complete protein, providing all the essential amino acids needed for muscle repair and growth.

Both milks support heart health, but in different ways. Oatmilk's soluble fiber (beta-glucans) helps lower cholesterol, while soy milk's isoflavones have also been shown to reduce LDL cholesterol.

Because oatmilk is higher in carbohydrates than soy milk, it can cause a greater blood sugar response. Unsweetened versions are recommended, especially for those managing blood sugar levels.

When it comes to environmental impact, oat production is generally considered more sustainable than soy, using less water and land. However, both have a significantly lower carbon footprint than traditional dairy milk.

Oatmilk is generally known for its naturally creamy and slightly sweet taste, which makes it a favorite for coffee and lattes. Soy milk offers a creamy texture as well but with a more nutty flavor.

Yes, both soy and oatmilk can be used for baking. Oatmilk's creaminess is often a plus, while soy milk's higher protein content can mimic dairy milk's function in some recipes.

For weight loss, both unsweetened versions are viable. Unsweetened soy milk is higher in protein for satiety, while unsweetened oatmilk is lower in calories. The best choice depends on whether you prioritize protein or fewer carbs.