What is the healthiest liquid for protein shakes?

October 9, 2025 •

4 min read

According to a 2024 review, the choice of liquid can significantly impact a protein shake's nutritional profile, flavor, and texture. So, what is the healthiest liquid for protein shakes, and how do different options affect your health and fitness goals?

Quick Summary

The best liquid for a protein shake depends on individual health and fitness objectives. Choices like water, milk, and plant-based alternatives offer distinct benefits regarding calories, protein, and texture, catering to goals from weight loss to muscle gain.

Key Points

Water is the leanest choice: Ideal for weight loss and quick absorption, as it adds zero calories and keeps the shake light and simple.
Dairy milk boosts nutrients: Best for muscle gain and satiety, providing extra protein, calcium, and a creamier, more satisfying texture.
Plant-based milks are customizable: Offers dairy-free options with varied profiles; almond milk is low-calorie, while soy milk is high-protein.
Consider unsweetened options: To avoid excess sugar, opt for unsweetened plant-based milks or dilute high-sugar juices with water.
Align your liquid with your goal: Choose based on whether you need low calories (water, almond milk) for weight loss or extra fuel (dairy milk, soy milk) for muscle gain.
Don't forget creative mix-ins: Other liquids like coconut water for electrolytes or kefir for probiotics can add variety and different benefits.

Your choice of liquid for a protein shake might seem minor, but it can play a significant role in your nutritional intake, flavor experience, and overall health outcomes. There is no single 'healthiest' option, as the best liquid for you depends on your specific dietary needs, fitness goals, and taste preferences. Let's break down the most popular choices to help you make an informed decision.

The Case for Water: Simplicity and Hydration

Mixing protein powder with water is the most straightforward approach. It offers distinct advantages, especially for those who are calorie-conscious or prefer a simple, clean taste.

Benefits of Using Water

Zero Calories: Water adds no extra calories to your shake, making it an excellent choice for individuals on a weight loss or calorie-controlled diet.
Pure Hydration: Water helps replenish fluids lost during exercise, aiding in overall hydration.
Fast Absorption: Protein mixed with water is absorbed relatively quickly, which can be beneficial for post-workout muscle recovery.
Highlights Flavor: For those who enjoy the taste of their protein powder, water provides a neutral base that allows the flavor to stand out without interference.

When to Use Water

For weight management and fat loss.
When your primary goal is hydration and quick protein delivery.
If you're on a budget (water is free).

Dairy Milk: The Creamy, Nutritious Option

Long considered the standard mixer for protein shakes, dairy milk offers a richer, creamier texture and adds significant nutritional value.

Benefits of Using Dairy Milk

Extra Protein and Nutrients: A single cup of milk can add an extra 8 grams of high-quality protein, along with essential nutrients like calcium and vitamin D.
Enhanced Satiety: The combination of protein, carbs, and fats in milk can make your shake more filling and satisfying, which helps curb hunger between meals.
Superior for Muscle Gain: The extra protein and calories are ideal for individuals looking to build muscle or bulk up.
Creamier Texture: Milk creates a thick, milkshake-like consistency that many people find more palatable and enjoyable.

When to Use Milk

For muscle building and mass gain.
As a meal replacement to promote satiety.
If you prefer a thicker, creamier shake.

Plant-Based Milks: The Dairy-Free Alternative

For those who are lactose intolerant, follow a vegan diet, or simply prefer a dairy-free option, plant-based milks offer a versatile solution. Nutritional profiles vary significantly among different types, so it's important to choose wisely.

Popular Plant-Based Options

Almond Milk: One of the lowest-calorie and lowest-carb plant-based options, making it a good choice for weight management. Choose unsweetened versions to avoid added sugars.
Oat Milk: Provides a creamier texture than almond milk due to its higher carbohydrate content. It can be higher in calories and is best suited for those needing extra energy.
Soy Milk: Offers a protein content comparable to dairy milk, making it a complete protein source for vegans. It's a great all-around nutritional choice.
Coconut Milk: Adds a unique tropical flavor and healthy fats. It's lower in protein and higher in saturated fat, so it's not ideal for low-calorie diets.

Comparison of Common Protein Shake Liquids


Liquid	Calories per cup (approx.)	Protein per cup (approx.)	Consistency	Best For
Water	0	0g	Thin, light	Weight loss, quick absorption, hydration
Skim Milk	80-90	8g	Creamy	Muscle gain, satiety, balanced nutrition
Unsweetened Almond Milk	30-40	1g	Thin, slightly creamy	Calorie control, low-sugar diet
Unsweetened Soy Milk	80-100	7-8g	Creamy	Vegan muscle gain, balanced nutrition
Unsweetened Oat Milk	120-130	3-4g	Thick, creamy	High energy needs, richer texture

Creative Mix-Ins and Considerations

While water, milk, and plant-based milks are the primary bases, other liquids can add variety and different nutritional benefits.

Juices and Other Liquids

Fruit Juice: Can be used for a quick energy boost, especially pre-workout, due to its carbohydrate content. However, be mindful of the high sugar levels.
Coconut Water: Rich in electrolytes like potassium, it’s an excellent option for rehydration post-exercise.
Kefir: A fermented dairy drink packed with probiotics for gut health. It works well with fruity protein powders.

How to Choose Your Liquid

Identify Your Goal: Are you trying to lose weight, gain muscle, or simply add more protein to your diet? Your objective is the most crucial factor.
Consider Dietary Needs: Are you lactose intolerant, vegan, or managing other allergies? This will narrow your choices significantly.
Evaluate Macronutrients: Look at the calories, protein, and fat content of each liquid to see how it aligns with your daily macro targets.
Prioritize Taste and Texture: If you don't enjoy the taste or consistency of your shake, you're less likely to stick with it. Experiment to find what you like best.

Conclusion

Deciding what is the healthiest liquid for protein shakes comes down to your personal health journey. For those focused on a calorie deficit, water or unsweetened almond milk is the simplest and best choice. For individuals aiming for muscle growth, dairy milk or protein-rich soy milk provides extra fuel and nutrients. The most important thing is to choose a liquid that supports your goals and keeps you consistently fueled.

For more in-depth nutritional information on protein, consult Healthline's detailed guide.

Frequently Asked Questions

For weight loss, mixing protein powder with water is generally better. It keeps your shake low in calories, allowing you to meet your protein needs without adding extra fat and sugar that milk contains.

Yes, milk can slow down protein absorption compared to water due to its fat and casein content. This can be beneficial for longer-lasting satiety but less so for rapid post-workout recovery.

Yes, plant-based milks like soy, almond, and oat milk are excellent substitutes. Soy milk offers similar protein levels to dairy, while almond and oat milk are good low-calorie or creamy options, respectively.

If you are lactose intolerant, unsweetened almond milk, soy milk, or water are your best options. Soy milk provides the most protein, while water and almond milk are lowest in calories.

Yes, you can mix protein powder with fruit juice for flavor and a quick energy boost from carbohydrates. However, be mindful of the high sugar content, especially if you are watching your calorie intake.

To improve the flavor of a water-based protein shake, try using cold water or adding a few ice cubes for a chilled beverage. You can also add a pinch of spices like cinnamon or nutmeg.

For muscle gain, dairy milk is often considered superior because it provides additional protein, calories, and carbohydrates to support muscle synthesis. Fortified soy milk is a good vegan alternative.