In today's health-conscious society, it's more important than ever to understand exactly what we're putting into our bodies. One question you might have found yourself asking is, "Is there sugar in milk?" The answer is yes. We have developed this comprehensive guide to help explain how the unique sugar in milk compares with sugars in other foods and drinks, and why and for whom it may or may not be a health concern.

One quick and easy way to see if milk contains sugar and how it will affect your blood sugar is to use the January app. It's completely free to download and use, and it allows you to look up foods and drinks and see their calories, macros, and predicted blood sugar impact—and even suggests healthy alternatives for you to consider.

Download the free January app here.

Understanding the basics: What is sugar?

Before we delve into the relationship between sugar and milk, it's important to understand what sugar is. Sugar is a type of carbohydrate, and carbs are a macronutrient category that includes sugars, starches, and fibers. (The other macronutrient categories are proteins and fats.) When you eat carbs, the sugars and starches get broken down into glucose, which gets released into the bloodstream. Your body then taps the glucose for energy when you need it, and stores any excess glucose for energy later. Before we describe the different types of sugar, let’s jump straight to the big issue of how, from any combination of sugar types, an excessive total amount of sugar consumption could affect you.

What happens when we consume too much sugar? 

Our bodies are designed to handle moderate sugar intake, but overconsumption can lead to various health issues. When we consistently consume more sugar than our bodies need, the excess is converted into fat and stored in adipose tissue, leading to weight gain and obesity. In addition, excessive sugar consumption can contribute to the development of insulin resistance and in turn lead to type 2 diabetes (T2D) — so if you have diabetes or are at risk for it, see our companion article, Can diabetics safely drink milk?

Excessive sugar consumption is also linked to a litany of other medical issues, including other cardiometabolic disorders (hyperinsulinemia, dyslipidemia, hypertension and more), nonalcoholic fatty liver disease (NAFLD), bone loss, gastrointestinal (GI) disorders, kidney problems, neurodegenerative disorders (such as Alzheimer’s disease), certain cancers, gout, and tooth decay.

Simple sugars 

Sugar takes many forms. So-called “simple sugars” are found in a variety of natural foods including fruits, vegetables, milk and honey, but they are also processed and added to hundreds of foods like cakes, candies, soda, fruit juice, ketchup, sauces, ice cream, even yogurt. Because they are “simple,” these carbs provide a quick source of energy to the cells, which happens when the production of insulin is triggered. In healthy individuals, when simple sugars are consumed in excess, they are most often converted into energy stores that can be kept and used later, either as glycogen (stored by the liver and muscles) or fat (ectopically stored as triglycerides in adipose tissue, liver, and muscle). However, even if individuals can successfully process large amounts of sugar without developing diabetes, they may become obese — which in and of itself is associated with a host of metabolic and cardiovascular disorders. For those individuals who don’t have enough insulin to move glucose out of the blood, or the insulin is ineffective (aka insulin resistance), blood glucose levels can stay chronically high — leading to a host of health issues, including diabetes. Learn more: The Link Between Blood Sugar and Diabetes. Simple sugars fall into 4 categories:

Glucose is a monosaccharide, a carbohydrate in its simplest form: it can’t be broken down any further. Corn syrup is an example of a glucose food source. Glucose is what your body primarily uses for energy. It raises blood sugar levels more rapidly than sucrose, fructose or lactose, and it triggers the production of insulin to move glucose from your blood into your cells for energy (or into the liver or muscles for later use).

Fructose, also a monosaccharide, is found naturally in fruits, honey, and root vegetables.  Compared with glucose, fructose causes a more gradual rise in blood sugar levels. But that doesn’t mean you should go crazy eating fructose-rich foods, which have been linked to high triglycerides and fatty liver disease. In fact, one study found that of all three sugars, added fructose — either as a part of added sucrose or as the main component of high-fructose sweeteners — may be the most harmful to your health and put you at greatest risk of diabetes. However, naturally occurring fructose found in whole foods like fruits and vegetables had the opposite effect, and may even have a protective effect against diabetes. 

Sucrose, or table sugar, comes from cane or beet sugar and is a disaccharide made up of one glucose molecule and one fructose molecule — so it has to be broken down before your body can use it for fuel. Sucrose is also found naturally in a variety of carbohydrate foods, many of which are foods with otherwise healthy nutritional value — such as apples, oranges, bananas, peas. Sucrose is also added to foods to give them that sweet taste so many of us crave — such as sugar-sweetened beverages, ice cream and other desserts, ketchup, fruit juice, even yogurt. 

Lactose is the natural sugar found in milk and other dairy foods (ice cream, yogurt, cheeses, etc.), making it an essential component of dairy products. Lactose forms when two other sugars, glucose and galactose, join together. For the body to digest lactose, it uses a natural enzyme, called lactase, to break lactose down. (If your body doesn’t make enough lactase, you may not be able to break down or absorb lactose properly, which can lead to symptoms of lactose intolerance. For those individuals, lactose-free milk options are available, including products made from rice, almond, soy, flax, coconut, hemp, and cashew: see our comprehensive analysis, What are the healthiest milk alternatives? However, lactose-free milk still contains about the same amount of carbohydrates/sugars as does regular milk.)

Starches (or complex sugars)

Starches are essentially complex sugars; they are polysaccharides — long chains of various sugars (monosaccharides and disaccharides). Consequently, after consumption, they will be broken down into sugars at a much slower rate, tending to spike blood sugar levels less than do simple sugars. 

Many starches also contain fiber, to varying degrees. Fiber is a type of carb that your body can’t digest. In other words, it can’t be broken down into sugar molecules, so it hasn’t been shown to have any negative effect on your blood sugar levels. Furthermore, fiber becomes food for your gut microbiome, resulting in important byproducts such as short-chain fatty acids (SCFAs), signaling molecules that appear to play a role in producing bioactives that help steady blood glucose, regulate hunger, and reduce inflammation — all important for diabetes management. Learn more about fiber and its importance in diabetes management.

Complex carbs that are high in starch compounds, but not as high in fiber, include many cereals, white bread, corn, refined pasta and white rice. While complex, remember that even these foods, being polysaccharides, do ultimately get broken down in your body to glucose (as well as some fiber and other types of molecules). Therefore, complex carbs that are especially low in fiber and above-average or high on an easy-to-look up Glycemic Index (GI) could very well contribute to higher blood glucose levels. Hence, these are “the low-quality carbs.” (An example of one complex carb offender: white rice. See our article, Rice and Diabetes, for details.)

By contrast, complex carbs that are much higher in fiber and lower on the Glycemic Index include many whole fruits, vegetables, nuts, lentils, beans and whole grains. Many of these are “the high-quality carbs,” such as broccoli, brussels sprouts, almonds, chickpeas and kidney beans. Learn more: Confused about carbohydrates?

What’s in milk?

Milk, an animal food source (unless it’s a plant-based alternative, which we’ll discuss later), is a common staple in many diets around the world because it's high in protein and rich in vitamins, minerals, and other essential nutrients. Milk is a complex liquid that consists of various components, each playing a crucial role in its composition. Apart from its nutritional value, milk also contains several bioactive compounds that contribute to its health benefits.

Let’s first be clear about milk’s positives: 

1. One serving of milk provides 13 essential nutrients. Two of these, calcium and vitamin D, are vital for bone health. When considering calcium, dairy milk naturally has about 300 milligrams per cup, and dairy products generally are considered the best absorbed source of calcium. Many soy or almond milks are fortified with calcium to at least match the amount of calcium in dairy milk. That said, your body may not absorb all of the calcium in soy milk since soy contains a natural compound (phytate) that inhibits calcium absorption.
   
   
2. Milk contains protein that helps build and repair muscles. According to Mayo Clinic, “dairy milk takes the protein title” with a little over 8 grams per cup. (Soy milk comes in a close second with about 7 grams per cup. Traditional almond milk lags behind with just 1 gram per cup. Of note, some newer nut milk varieties have added pea protein.)
   
   
3. Milk is rich in B vitamins that contribute to healthy metabolism and energy; provides immune-supporting zinc, selenium and vitamins A and D; offers a good source of heart-healthy potassium; and is an excellent source of iodine to support a baby's brain development during pregnancy. 

Conversely, there are several points of concern regarding what’s in milk: 

Is there fat in milk?

Milk, being an animal food source, does contain saturated fat — the kind of fat that the American Heart Association recommends limiting (to no more than 7% of calories in your overall diet) due to its association with heart disease, stroke, and metabolic disorders such as diabetes. Whole milk contains approximately 3.5% fat, while low-fat types have less, and skim milk’s fat content is negligible. (Soy and almond milks contain about 2 to 4 grams of fat per cup, but those fats are predominantly healthy, monounsaturated and polyunsaturated fats: learn more.) On the other hand, the pros/cons of milk fat remain controversial and are still under study. A growing body of research finds that the saturated fats in milk — even in whole cow’s milk — may be less harmful for adults than previously thought. A 2020 review in the Journal of Cardiology concluded that “several foods relatively rich in saturated fatty acids (SFAs), such as whole-fat dairy … are not [our emphasis] associated with increased CVD or diabetes risk.” The authors went on to argue that while “SFAs increase low-density lipoprotein (LDL) cholesterol, in most individuals, this is not due to increasing levels of small, dense LDL particles, but rather larger LDL particles, which are much less strongly related to CVD risk.” Future research will hopefully shed more light on the validity of this distinction between small and larger LDL cholesterol particles.

Important side note: Leading medical organizations now recommend whole milk over reduced-fat milk for children. For example, the American Academy of Family Physicians (AAFP) recommends two 8-oz servings of cow's milk per day in toddlers to maintain adequate vitamin D and iron stores, and children one to two years of age should drink whole milk rather than reduced-fat milk unless they are deemed at risk of obesity or cardiovascular disease. Some studies even indicate that the early introduction of reduced-fat milk ultimately may increase the risk of obesity, while plant-based alternatives (including almond, rice, coconut, and hemp milks) tend to have less protein and fat compared with cow's milk and have been associated with decreased adult height and lower vitamin D levels.

Is there protein in milk?

While milk’s high level of protein is generally considered a positive, too much of a good thing isn’t advised, either. And most Americans consume plenty of protein from a variety of sources. As the American Diabetes Association (ADA) has stated, research is inconclusive regarding the ideal amount of dietary protein to optimize either glycemic control or cardiovascular disease (CVD) risk. While some research has found successful management of T2D with meal plans including slightly higher levels of protein (20–30%), which may contribute to increased satiety, protein intake may enhance or increase the insulin response to dietary carbohydrates, suggesting that carbohydrate sources high in protein (such as milk and nuts) should be avoided when an individual with diabetes is at risk for a swing down in blood sugar (hypoglycemia) due to the potential concurrent rise in endogenous insulin. Also, research such as this 2016 Harvard study found that people with prediabetes who consumed a diet high in animal protein had a 13 percent higher risk of developing T2D compared to those who consumed the least amount of animal protein. (Vegetable sources of protein, on the other hand, gave them a bit of protection from the disease.) 

Is there sugar in milk?

Dairy milk does contain sugar in the form of lactose. (As mentioned previously, even lactose-free milk contains sugar.) A 1-cup serving of milk contains about 12 grams of this lactose sugar. Compare that with 30g of sugar equivalents in the same size glass of orange juice. While the impact of lactose differs in some respects from other sugars, lactose is still a sugar, and so can raise blood glucose levels if consumed in excess. (However, when lactose is broken down and absorbed into your bloodstream, it provides energy without causing as significant a rise in blood sugar as do other simple sugars.) But be wary of “added sugars”: While unflavored white dairy milk and unsweetened soy and almond milk contain no added sugars, many plant-based alternative milks (unless they are “unsweetened”) may contain 4 or more grams of added sugars, as does chocolate milk. (Some plant-based milks contain naturally occurring sugars, too, such as coconut or oat, but those have typically less than a few grams of sugar per serving.) So reading the labels is imperative.

As you can see in the image below from the free January app, this specific milk doesn't have a huge impact on blood sugar, but comparing it to unsweetened almond milk, it's clear that the almond milk will have an even lower impact — and contains far fewer calories per cup. Download the January app and compare different kinds of milk to see how you personally respond, and of course, take a look at the macros to see what milk to choose during your next grocery haul.

Learn all about milk and what it contains in our comprehensive analysis; What are the healthiest milk alternatives?

The bottom line: Is milk healthy?

Studies distinguishing the precise health impacts of milk, and those of the many kinds of milk available, from the vast array of other dairy products (yogurt, cheese, etc.), remain few in number and/or of debatable quality. However, most research to date fails to connect milk consumption with any significant increase in the risk for or exacerbation of major cardiometabolic disorders, or even finds that milk may reduce such risks or aid in managing existing disease. A 2021 prospective cohort study of subjects with prediabetes found lower T2D incidence after increased consumption of low-fat dairy (milk or yogurt), but did find that T2D incidence rose in a group consuming cheese. An important 2022 JAMA study, which was a systematic review of 28 dose-response meta-analyses that examined all foods and all nutrients to assess their association with both diabetes and cardiovascular incidence, concluded that the only dairy product associated with protective abilities against diabetes was yogurt. Regarding milk, its impact (along with eggs and cheese) was either null or there were too few or inferior-designed studies to make any conclusions.

On balance, the nutritional value of milk still wins over most experts, especially because milk contains a natural form of calcium that has superior absorption properties. The USDA continues to recommend that Americans (age 9 and over) consume a recommended 3 cups/day of any low-fat dairy products (assuming a 2,000 calorie day), stating in the 2020-25 Dietary Guidelines for Americans that other products sold as “'milks” but made from plants (e.g., almond, rice, coconut, oat, and hemp “milks”) are not included as part of “the dairy group” because their overall nutritional content is not similar to dairy milk and fortified soy beverages. 

Most other major medical organizations — including groups (e.g., the American Diabetes Association) addressing those at risk for or currently diagnosed with diabetes — also continue to recommend dairy foods, despite the sugar content, for their overall beneficial nutrient density. However, the ADA recommends watching out for how milk factors into an individual’s total daily carbohydrate and calorie consumption. The implication: Dairy products should be consumed in moderation if carb intake from other carb categories, or total calorie consumption per day, is trending high. 

Milk as one part of an individualized food matrix

The concerns about sugar, potentially unhealthy fats, or any number of other food ingredient issues aside, remember it’s the foods that you eat in total — taking into account the combinations of different types and quantities of foods you eat per meal and per day — that probably matters much more than the individual nutrients you consume or the composition of any one food, milk included. As one scientist aptly stated in a 2020 study, “the health effects of foods cannot be predicted by their content in any nutrient group without considering the overall macronutrient distribution.” Some researchers are calling this overall food distribution the “food matrix,” and the importance of this concept cannot be denied.

Here’s just one fascinating example of how two different foods may produce a different end-result, when combined, than would each if consumed alone — and one of these foods is milk. In a 2023 study, it was determined that consuming coffee with milk may inhibit inflammation more than black coffee. (Inflammation, particularly chronic, low-grade inflammation, can lead to a wide range of chronic conditions, including metabolic syndrome, type 2 diabetes, cardiovascular disease, and non-alcoholic fatty liver disease, to name a few.) As we discussed in our article, Does caffeine increase blood pressure?, coffee contains naturally-occuring, beneficial antioxidants, called polyphenols. In the 2023 study, scientists determined that the polyphenols in coffee, when they’re mixed with the amino acids (the building blocks of proteins) in milk, were twice as effective at fighting inflammation in the cells than were the polyphenols in black coffee alone!

As important, food impacts are highly individualized. How each of our bodies reacts to various milks, and to the sugars and other ingredients in those milks, may vary considerably. Monitoring your food intake while wearing a continuous glucose monitor (CGM), together with an app (such as the January AI platform) that allows you to leverage heart rate and glucose data, may help you to align your health habits in precisely the way your body needs. 

Key takeaways

Is there sugar in milk? In conclusion, yes, there is sugar — a type of carbohydrate — in animal milks, whether the milk comes from cows, goats or other mammals. That natural sugar in milk is called lactose. And lactose-free milk is not carbohydrate-free, either, as it contains lactose together with the enzyme lactase (to modify the way lactose is digested). While lactose is a type of sugar that typically has less of an impact on blood sugar levels compared to other forms of sugar, those watching their total carbohydrate intake should be aware of how much milk, and what type, they are drinking. Even plant-based or alternative milks may contain sugars, either from natural sources or, in more cases, from sugars added in the manufacturing process. All in all, leading medical organizations, even those representing individuals with diabetes (who must be particularly wary of foods that can spike their blood glucose levels), continue to recommend dairy consumption, milk included, because of the latter’s nutrient density on so many fronts (including high levels of readily absorbable calcium and vitamin D, among other nutrients). Milk’s other components, particularly its fat content, are the stuff of more intense debate, frankly, than is the sugar content, with some groups continuing to advise avoidance of high-fat milks (except for children) because that fat is saturated, or “the bad fat”; whereas other research points to a neutral impact from the fats in milk and other dairy products, or even a potentially protective role.  

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