Yes, Lactose-Free Yogurt Has Whey Protein

December 2, 2025 •

3 min read

Over 65% of the world's population has some degree of lactose intolerance, leading many to seek lactose-free dairy products. Many are surprised to learn that because these products are still dairy-based, lactose-free yogurt does have whey protein and casein, the two primary milk proteins.

Quick Summary

Lactose-free yogurt contains whey protein because the lactase enzyme treatment removes only the milk sugar (lactose), not the milk proteins (casein and whey). This allows individuals with lactose intolerance to consume dairy-based yogurt and benefit from its high-quality protein content.

Key Points

Lactose and Protein are Different Molecules: Lactose is a sugar, while whey is a protein. Making a dairy product lactose-free targets the sugar, leaving the protein unaffected.
Enzymatic Breakdown is the Key: The lactase enzyme added to lactose-free yogurt specifically breaks down lactose, but it does not interact with or remove the protein content.
Fortification is Common: Some lactose-free Greek yogurts are even fortified with additional lactose-free whey protein concentrate to increase their protein density and improve texture.
Not a Dairy-Free Product: Lactose-free products are still dairy-based and contain milk proteins. Dairy-free products, made from plant sources, contain no whey protein.
Benefits for Lactose-Intolerant Individuals: This allows people with lactose intolerance to consume dairy and get the complete protein and other nutritional benefits of milk.
Nutritionally Similar to Regular Yogurt: The protein, fat, and calorie counts in lactose-free yogurt are essentially the same as in regular yogurt, as only the lactose sugar has been altered.

Understanding the Milk Components

To understand why lactose-free yogurt still contains whey protein, it's essential to know the basic components of milk. Milk is primarily composed of water, milk sugar (lactose), fat, vitamins, and two main types of protein: casein and whey. Casein makes up about 80% of the protein in milk, while whey comprises the remaining 20%.

Casein: These are the solid, insoluble proteins that form the curds during the cheese and yogurt-making process.
Whey: This is the liquid byproduct that is separated from the curds. It contains water-soluble milk proteins and a high concentration of branched-chain amino acids, making it valuable for muscle growth and repair.
Lactose: A disaccharide sugar that requires the lactase enzyme for proper digestion.

The Lactose-Free Production Process

The process of making yogurt lactose-free does not involve removing the proteins. Instead, it targets the milk sugar. Manufacturers achieve this primarily through enzymatic hydrolysis:

Adding Lactase: The enzyme lactase is added to the milk before or during the fermentation process.
Splitting the Lactose: Lactase breaks down the complex lactose molecule into two simpler, more digestible sugars: glucose and galactose.
Maintaining Protein Content: Since the process only targets the lactose sugar, the casein and whey proteins remain intact. This means the resulting yogurt has the same amount and type of protein as its traditional counterpart.

Some manufacturing processes also use ultrafiltration to remove some of the lactose, but the key step remains the addition of lactase. This is a crucial distinction from dairy-free or plant-based yogurts, which are made from non-dairy sources like almonds or coconut and contain none of the milk proteins.

Why This Matters for Lactose-Intolerant Consumers

For many who are lactose intolerant, the fear of gastrointestinal distress leads them to avoid all dairy, missing out on important nutrients. Lactose-free yogurt offers a solution by providing the full nutritional benefits of dairy without the discomfort caused by lactose. It is a source of high-quality protein, which is excellent for satiety, muscle health, and overall nutrition.

Comparison Table: Lactose-Free vs. Dairy-Free Yogurts


Feature	Lactose-Free Yogurt	Dairy-Free Yogurt (e.g., Almond, Coconut)
Source	Dairy milk (cow, goat, etc.)	Plant-based milk (almond, coconut, soy, oat)
Lactose Content	Less than 0.01% (virtually none)	Zero
Whey Protein	Yes, contains both whey and casein	No, contains no milk proteins
Casein Protein	Yes	No
Enzyme Added	Lactase	None
Common Protein Source	Milk proteins (whey and casein)	Soy, pea, almond, or coconut protein
Texture	Similar to regular dairy yogurt	Varies, often stabilized with thickeners

Potential Protein Differences in Strained Yogurts

Another factor influencing protein content is the straining process used to make Greek-style yogurt. This process removes excess liquid (whey), concentrating the remaining milk solids, including the casein. However, even after straining, some whey protein remains, and lactose-free versions can be explicitly fortified with added lactose-free whey protein concentrate (LFWPC) to boost their protein levels and enhance texture. A study published in Foods confirmed that adding LFWPC to lactose-free Greek yogurt significantly increased its protein concentration.

Key Takeaways

Lactose-free yogurt is made from dairy milk, so it contains the natural milk proteins, casein and whey.
The lactase enzyme is added to break down the lactose sugar, not to remove the proteins.
Strained varieties like Greek yogurt have a higher protein concentration due to the removal of liquid whey during processing.
Unlike dairy-free alternatives, lactose-free yogurt provides the complete protein profile of traditional dairy products.

Conclusion

In conclusion, the answer to the question "Does lactose-free yogurt have whey protein?" is a definitive yes. The process of making yogurt lactose-free involves the enzymatic breakdown of lactose, leaving the valuable whey and casein proteins fully intact. This distinction is vital for consumers with lactose intolerance who want to enjoy the nutritional benefits of dairy, including high-quality protein, without experiencing digestive issues. Always check the label to ensure it is a milk-based, lactose-free product and not a plant-based, dairy-free alternative, as the latter will not contain whey protein. For more information on the production process and the nutritional benefits of lactose-free dairy, the National Institutes of Health provides excellent resources on its website.

Frequently Asked Questions

No, lactose-free yogurt is not dairy-free. It is made from cow's milk and still contains all the milk's natural proteins, including casein and whey. Dairy-free products are made from non-dairy sources like nuts or soy.

The protein content of lactose-free yogurt is essentially the same as regular yogurt because the lactase enzyme only breaks down the lactose sugar, leaving the protein composition unchanged.

No, if you have a milk protein allergy, you should not eat lactose-free yogurt. This product is still dairy-based and contains the same milk proteins, casein and whey, that can cause an allergic reaction.

Lactose-free Greek yogurt is strained to remove excess liquid, which concentrates the protein. While this process removes some whey, the resulting product has a higher overall protein density. Additionally, some brands add lactose-free whey protein concentrate.

Lactose-free milk tastes sweeter not because it contains more sugar, but because the lactase enzyme breaks lactose into its simpler, sweeter-tasting components: glucose and galactose.

Yes, whey protein is a high-quality, easily digestible protein rich in branched-chain amino acids (BCAAs). These are essential for muscle repair, growth, and overall body function.

The lactose is removed by adding a lactase enzyme to the milk. This enzyme specifically targets and breaks down the lactose sugar into glucose and galactose, leaving the protein molecules intact.