Milk is supposed to be simple: a basic, nutritious drink that’s been part of human diets for thousands of years. But if you’ve ever had a glass of milk and felt bloated, gassy, or just plain uncomfortable afterward, you know it’s not always that straightforward.
On our milk food page, we give it a digestibility score of 4/10 with an estimated digestion time of 2–3 hours. That’s below average, and for good reason. This article explains why milk can be challenging, who tends to struggle, and how to make it work better for your gut.
Why milk is often hard to digest
Milk gets its low digestibility score for several key reasons:
-
Lactose content.
Milk contains lactose, a sugar that requires the enzyme lactase to break down. Many people don’t produce enough lactase, especially as they age, leading to lactose intolerance symptoms. -
Liquid form moves quickly.
Unlike solid foods that sit in your stomach longer, liquid milk can move through your system quickly, which can cause a rapid spike in lactose that overwhelms your digestive enzymes. -
Casein protein can form curds.
The casein in milk can form curds in your stomach, which slows digestion and can feel heavy or uncomfortable. -
Fat content varies.
Whole milk has more fat, which can slow digestion and feel heavier. Skim milk has less fat but still has the lactose issue.
That combination explains why milk can feel fine for some people but cause bloating, gas, cramps, or diarrhea for others—even people who don’t think they’re lactose intolerant.
Who tends to struggle with milk?
Milk can be particularly challenging for:
-
People with lactose intolerance.
This is the most common issue. If you lack sufficient lactase enzymes, undigested lactose reaches your colon and gets fermented by bacteria, causing gas, bloating, and diarrhea. -
Those with IBS or sensitive stomachs.
Even if you’re not fully lactose intolerant, the lactose and proteins in milk can trigger IBS symptoms like bloating, cramping, and changes in bowel habits. -
People with dairy protein allergies.
Some people are allergic to casein or whey proteins in milk, which can cause more severe reactions than lactose intolerance. -
Anyone who drinks large amounts at once.
Even people who normally handle milk well can struggle if they drink too much at once, especially on an empty stomach.
If you fall into any of these categories, milk might need to be a "sometimes" drink rather than a daily staple, or you might need to switch to alternatives.
How to make milk easier to digest
If you want to enjoy milk without the digestive drama, try these strategies:
-
Choose lactose-free milk.
Lactose-free milk has the lactose pre-digested, so it won’t cause lactose intolerance symptoms. It tastes slightly sweeter but otherwise similar to regular milk. -
Start with small amounts.
A small glass (4–6 ounces) is often easier to handle than a large glass. You can gradually increase if it sits well. -
Drink it with food.
Having milk with a meal slows down digestion and can reduce the rapid lactose spike that causes symptoms. -
Consider A2 milk.
A2 milk has a different protein structure that some people find easier to digest than regular A1 milk. -
Try fermented dairy instead.
Yogurt and kefir have less lactose due to fermentation and often sit better than plain milk. -
Use lactase supplements.
Over-the-counter lactase enzyme supplements can help you digest lactose if you take them before drinking milk.
The key is treating milk as a food that requires some planning, not a drink you can chug without consequences.
Milk vs other dairy for digestion
Compared with other dairy options, milk typically ranks lower for digestibility:
- Plain yogurt (9/10): Much easier due to probiotics and reduced lactose from fermentation.
- Cottage cheese (7/10): Easier due to lower lactose and pre-digested proteins.
- Milk (4/10): Harder due to high lactose and liquid form that moves quickly.
- Hard cheeses (3/10): Even harder due to high fat, but aged varieties have almost no lactose.
If you’re trying to keep dairy in your diet but want easier digestion, yogurt or cottage cheese are usually better choices than milk.
Simple test: is milk right for you?
Here’s a straightforward way to check your tolerance:
-
Pick a calm day.
Avoid testing during a stressful period or right after a heavy meal. -
Have a small glass (4–6 ounces) with a meal.
Don’t drink it on an empty stomach. Have it with breakfast or lunch. -
Track the next 3–4 hours.
Note any bloating, gas, cramps, diarrhea, or changes in energy or bathroom habits. -
Repeat on another day.
If both trials go smoothly, milk is likely safe for you in small amounts. If symptoms consistently appear, lactose-free milk or alternatives might be better.
Remember: a 4/10 digestibility score means milk is usually challenging to digest. Your individual tolerance might be better or worse, but the average person will find it difficult.
The bottom line
Milk is a basic food, but it’s not always easy to digest. Its 4/10 digestibility score reflects that it’s high in lactose, moves quickly through your system, and can cause issues for many people—even those who don’t think they’re lactose intolerant.
If you want to enjoy milk without digestive drama, try lactose-free versions, start with small amounts, drink it with food, or consider fermented dairy alternatives like yogurt. If you’re lactose intolerant, have IBS, or have dairy allergies, milk might need to be a "sometimes" drink rather than a daily staple.
The key is treating milk as a food that requires some planning and awareness, not a drink you can consume without consequences. Small amounts, smart choices, and listening to your body can help you enjoy milk without paying for it with digestive discomfort.
Related reading: Want to compare milk with other dairy options? Check out our article on Milk vs Other Dairy: Which Is Easiest on Your Stomach?