Is there too much sugar in oat milk? Unpacking the sweetness

December 21, 2025 •

3 min read

According to Oatly, the sugars in their original oat milk are created during an enzymatic production process that breaks down starches into simpler sugars like maltose. This natural processing can make consumers question: is there too much sugar in oat milk, and how does it compare to other alternatives? The answer depends heavily on the brand and type you choose.

Quick Summary

The sugar content in oat milk is primarily influenced by the enzymatic process used during production, which converts starches into natural sugars like maltose. While many "unsweetened" versions have lower carbohydrate levels than sweetened counterparts, they can still cause a moderate blood sugar response due to the maltose content. Careful label reading and choosing truly low-sugar brands are essential for managing intake.

Key Points

Enzymatic Process: The natural sweetness in oat milk is primarily caused by an enzymatic process that converts the oats' starches into sugars like maltose.
Labeling Matters: Check the 'Total Sugars' on the nutrition facts, as even 'unsweetened' versions contain naturally occurring sugars from processing that count as 'added'.
Glycemic Response: Oat milk has a moderate glycemic index and can cause a blood sugar spike, particularly for individuals with diabetes, especially when consumed on its own.
Choose 'Unsweetened': The best way to reduce sugar intake is to select products specifically labeled 'unsweetened' and avoid flavored or barista varieties.
Low-Sugar Brands: Some brands offer lower-sugar options by filtering out sugars post-processing; checking the nutrition label is key to finding them.
Homemade Alternative: Making your own oat milk at home provides maximum control over ingredients and sugar content, but requires careful blending to avoid a slimy texture.
Balance is Key: To mitigate blood sugar spikes, pair oat milk with foods rich in protein, fiber, or healthy fats, or use smaller portion sizes.

Why Is Oat Milk Sweet?

Many consumers notice a natural sweetness in oat milk, even in "unsweetened" varieties. This taste comes from the manufacturing process where enzymes break down the complex starches in oats into simpler sugars, primarily maltose. This enzymatic hydrolysis creates the sweet flavor and creamy consistency characteristic of oat milk.

The Maltose Effect: How Sugars are Created

Enzymatic Processing: Enzymes are added to the oat and water blend to convert starches into smaller sugars.
Maltose: This disaccharide sugar is a main product of the breakdown and has a relatively high glycemic index.
FDA Labeling: Due to processing, these naturally created sugars are classified as 'added sugar' on nutrition labels. Even unsweetened options can contain several grams.

Oat Milk vs. Other Milks: A Nutritional Comparison

Understanding the sugar content of oat milk is easier when compared to other common milk types. Nutritional values vary widely across different milk bases and brands.

Comparison Table: Oat Milk vs. Other Milks (per 1 cup, unsweetened or plain)


Nutrient	Unsweetened Oat Milk	Unsweetened Almond Milk	Unsweetened Soy Milk	Whole Dairy Milk
Calories	~90–120	~30–40	~80–100	~146
Total Fat	~1.5–5g	~2.5–3g	~4–5g	~8g
Carbohydrates	~13–20g	~1–2g	~3–4g	~12g
Total Sugars	~3–7g (natural)	~0–1g (natural)	~1–2g (natural)	~12g (lactose)
Protein	~2–4g	~1–2g	~6–8g	~8g
Fiber	~1–2g	~1g	~1g	0g

Health Implications of Oat Milk Sugar Content

The sugars naturally present in oat milk can affect blood sugar levels, similar to added sugars. While generally fine for healthy individuals in moderation, those managing conditions like diabetes should be mindful.

Managing Blood Sugar and Oat Milk

Glycemic Index: Oat milk has a moderate GI, potentially causing a moderate blood sugar increase, particularly when consumed alone.
Pairing: Combining oat milk with protein, fiber, or healthy fats can help slow sugar absorption and mitigate spikes.
Portion Size: Smaller quantities have a lesser impact on blood sugar.

How to Choose Low-Sugar Oat Milk Brands

Selecting a low-sugar oat milk requires careful label examination.

Label Reading Checklist

Look for "Unsweetened": Always start with unsweetened varieties to avoid added sugars.
Check 'Total Sugars': Examine the nutrition panel for the 'Total Sugars' value, as this includes sugars from processing. Aim for the lowest number.
Seek Low-Sugar Options: Some brands specifically offer low or zero-sugar options designed to minimize sugar content.
Simple Ingredients: Choose brands with minimal ingredients beyond oats and water, avoiding unnecessary additives.

Making Your Own Oat Milk for Maximum Control

Homemade oat milk offers the greatest control over ingredients and sugar content, although texture may differ from commercial versions.

Simple Homemade Oat Milk Recipe

Ingredients: 1 cup rolled oats, 4 cups cold water.
Instructions: Blend cold water and rolled oats for 30-40 seconds to avoid sliminess. Strain through a fine-mesh sieve or cheesecloth without squeezing the pulp. Store in the fridge for up to 5 days and shake before use.

Conclusion

Determining if there is too much sugar in oat milk depends on the specific product. Unsweetened versions contain naturally occurring sugars from processing, while sweetened types have added sugars. For those monitoring sugar intake, opting for unsweetened varieties with low total sugars is key. Homemade oat milk offers the most control. By reading labels and consuming in moderation, oat milk can fit into a healthy dietary pattern.

Finding More Information on Sugar Content

For more information on the enzymatic process and sugar content, consult resources from oat milk manufacturers, registered dietitians, or reputable nutrition websites.

Key Takeaways

Processed Sugars: Natural sweetness comes from maltose, a sugar created during the enzymatic breakdown of starches.
Brand Variation: Sugar content varies by brand; always check the 'Total Sugars' on the label.
Blood Sugar Impact: Even unsweetened oat milk can cause a moderate blood sugar rise due to its carbohydrate content.
Healthiest Choice: Unsweetened versions with minimal additives or homemade oat milk are preferable for lower sugar intake.
Diabetic Care: Individuals with diabetes should consider portion size and pairing with protein/fiber to manage blood sugar.

Frequently Asked Questions

The sugar in unsweetened oat milk comes from the natural processing of the oats. Enzymes are used to break down the oats' complex starches into simpler, smaller sugar molecules, primarily maltose, which creates a naturally sweet taste and creamy texture.

People with diabetes can drink unsweetened oat milk in moderation, but they should be mindful of its carbohydrate content and glycemic impact. It's recommended to pair it with protein or fiber to help stabilize blood sugar levels and to always check the nutrition label for total sugars.

The sugar in oat milk (maltose) and cow's milk (lactose) are different types. While cow's milk has naturally occurring lactose, some oat milks have less total sugar. However, because maltose has a higher glycemic index, it can affect blood sugar more quickly than the lactose in cow's milk.

For health-conscious consumers, unsweetened oat milk is almost always the better option. Sweetened versions contain a significant amount of added sugar, while the sugars in unsweetened oat milk are a natural result of the manufacturing process, making them a lower-sugar choice.

To choose a low-sugar oat milk, first look for the 'unsweetened' label. Next, check the nutrition facts panel for the lowest possible 'Total Sugars' number. Some brands also offer 'Zero Sugar' or enzyme-free versions, which are specifically designed to have less sugar.

Making oat milk at home allows you to control the ingredients completely, avoiding added sugars found in commercial sweetened versions. While the oats themselves still contain carbohydrates that convert to sugar, homemade versions contain only naturally occurring sugars.

To prevent a slimy texture when making homemade oat milk, use cold water and blend for no more than 30-40 seconds. Most importantly, do not squeeze the oat pulp during straining, as this releases starches that create the slimy consistency.