Do Dairy Products Upset Your Stomach? Understanding Lactose Intolerance and Finding Foods That Suit Your Body

“I eat yogurt every morning because it’s good for my health.”

“I drink milk for calcium.”

“I have a café latte every day.”

Many of us have habits like these.

Dairy products such as milk and yogurt can provide important nutrients, including protein and calcium.

However, even if a food is generally considered “healthy,” it does not mean that everyone can digest and absorb it in the same way.

After consuming dairy products, have you ever experienced:

• Stomach rumbling
• Bloating
• Increased gas
• Abdominal pain
• Loose stools or diarrhea

One possible reason is lactose intolerance.

What Is Lactose Intolerance?

Lactose intolerance is a condition in which the body cannot fully digest lactose, a type of sugar found in milk and dairy products, leading to digestive symptoms after consuming lactose-containing foods.

To digest lactose, our body needs an enzyme called lactase, which works in the small intestine.

Normally, lactase breaks lactose down into two simpler sugars:

Lactose → Glucose + Galactose

These sugars can then be absorbed by the body.

However, when the amount or activity of lactase is too low, some lactose may not be fully digested and absorbed in the small intestine.

The undigested lactose then moves into the large intestine, where it is fermented by gut bacteria.

This fermentation can produce gas, while undigested lactose can also increase the amount of water in the intestine. This may lead to symptoms such as bloating, abdominal pain, gas, and diarrhea.

What Happens Inside the Body?

1. Lactose enters the body through foods such as milk

↓

2. Lactase in the small intestine breaks down lactose

↓

3. If there is not enough lactase, some lactose remains undigested and moves into the large intestine

↓

4. Gut bacteria ferment the undigested lactose

↓

5. Gas and other changes in the intestine may cause bloating, abdominal pain, or diarrhea

This means that dairy products themselves are not necessarily “bad.”

What matters is how well your own body can digest lactose.

Why Can Milk Become Harder to Digest as We Get Older?

During infancy, lactase is normally active because babies need to digest lactose found in breast milk and other milk.

However, in many people, lactase activity decreases after childhood.

This means that someone may experience:

“I could drink milk without any problems when I was younger, but now it makes me feel bloated.”

The ability to digest lactose varies from person to person and is also influenced by genetic background and population.

Is Lactose Digestion More Difficult for Asians?

The ability to digest lactose differs between individuals, but there are also clear differences between populations.

Studies have reported that lactose malabsorption is relatively common among adults in East and Southeast Asian populations.

In Japanese People

One study of 18 healthy Japanese adults reported lactose malabsorption in approximately 89% of participants.

Another study involving Japanese participants found lactase deficiency in 92%, while only 13% experienced lactose intolerance after lactose consumption.

In Malaysians

A study involving 248 young Malaysian adults found lactase deficiency in 87.1% of participants.

However, only 19.8% were diagnosed with lactose intolerance accompanied by symptoms after consuming lactose.

This highlights an important point:

Having difficulty digesting or absorbing lactose does not necessarily mean that you will experience symptoms every time you consume dairy products.

Even when lactase activity is low, symptoms can vary depending on factors such as the amount of lactose consumed and the type of food.

Therefore, this does not mean that “Asians should avoid dairy products.”

What matters is understanding how your own body responds when you consume them.

Lactose Intolerance Is Different for Everyone

Lactose intolerance is not simply a matter of being able or unable to eat dairy products.

Symptoms can vary depending on:

• The amount of lactose consumed
• How much is consumed at one time
• Whether dairy is consumed together with other foods
• The type of dairy product
• How much lactose an individual can digest

Some people with lactose intolerance can consume small amounts of lactose without experiencing significant symptoms.

Therefore, being lactose intolerant does not necessarily mean:

“I have to completely stop eating dairy.”

Instead, it can be helpful to understand what you can tolerate and how much your body can comfortably handle.

Milk Upsets My Stomach — But What About Yogurt or Cheese?

This also varies from person to person.

Not all dairy products contain the same amount of lactose.

Some people may tolerate yogurt or certain hard cheeses better than milk.

There are also more options available today, including:

• Lactose-free milk
• Low-lactose products
• Plant-based milk alternatives

Instead of thinking,

“Milk makes me bloated, so I need to stop all dairy products,”

another approach is to find out which dairy products and what amounts work for your body.

“Healthy Food” and “Food That Suits Your Body” Are Not Always the Same Thing

This is one of the most important messages we want to share at KAMI.

There is a huge amount of health information around us:

“Eat yogurt for gut health.”

“Drink milk for calcium.”

“Eat this food because it’s healthy.”

Of course, these foods can provide nutritional benefits.

However, even when a food is generally considered healthy, it does not necessarily mean that it suits every individual body.

Eating is only the beginning.

Food goes through a process:

Eat
↓
Digest
↓
Absorb
↓
Transport nutrients where they are needed
↓
Use those nutrients within the body

This is why, at KAMI, we believe it is important not only to think about what you eat, but also to notice how your body responds after eating it.

Take Another Look at Your Everyday Habits

Are there foods or drinks you consume every day simply because you believe they are good for your health?

For example:

“I eat yogurt every morning, but I often feel bloated afterward.”

“I drink a café latte every day, but my stomach sometimes starts rumbling afterward.”

“I tend to have diarrhea when I drink a larger amount of milk.”

When something has become part of our daily routine, it can be surprisingly difficult to notice the connection between that habit and how our body feels.

One simple way to understand your body better is to keep a record of:

What you ate — How much — What time — How your body felt afterward

The purpose is not to immediately decide that a certain food is “bad.”

The goal is to start noticing patterns in your own body.

Instead of Giving Things Up, Find Alternatives That Suit Your Body

If you repeatedly experience discomfort after consuming dairy products, you do not necessarily need to completely give up the foods and drinks you enjoy.

Sometimes, simply changing your everyday choices can help.

For example:

Your daily café latte

Regular milk
↓
Lactose-free milk, soy milk, almond milk, or oat milk

If you enjoy milk itself, switching from regular milk to a lactose-free or low-lactose option may also be worth trying.

The important idea is:

Instead of focusing on restriction, increase the number of choices that work for your body.

However, plant-based milk alternatives are not nutritionally identical to cow’s milk.

Protein, calcium, vitamin D, and other nutrients vary between products, so it is important to check the nutrition label when choosing an alternative.

Nutrients to Consider When Reducing Dairy

If you significantly reduce or completely avoid dairy products, it is important to make sure your overall diet still provides enough:

• Calcium
• Vitamin D
• Protein

The goal is not simply to stop consuming dairy.

The goal is to adjust foods that do not suit your body while still getting the nutrients your body needs.

Both sides need to be considered.

Lactose Intolerance and Milk Allergy Are Not the Same

These two conditions are often confused, but they are different.

Lactose intolerance occurs when the body cannot adequately digest lactose, resulting mainly in digestive symptoms.

A milk allergy, on the other hand, is an immune reaction to proteins found in milk.

Because the mechanisms are different, they should not be considered the same condition.

It is also important to understand that a general food allergy test does not tell you all the foods your body has difficulty digesting.

When lactose intolerance is suspected, healthcare professionals may use other methods, such as a hydrogen breath test, depending on the individual situation.

Stomach Problems Do Not Always Mean Lactose Intolerance

Feeling bloated after drinking milk does not automatically mean that you have lactose intolerance.

Other gastrointestinal conditions can cause similar symptoms.

If your symptoms are severe, continue for a long time, or do not improve even after adjusting your diet, it is important to consult a healthcare professional rather than unnecessarily restricting foods on your own.

KAMI’s Message: Learn to Understand Your Own Body

We live in a time when health information is everywhere.

That is exactly why, instead of simply thinking:

“I heard this food is healthy, so I should eat it,”

we encourage you to ask yourself:

“How does my body actually feel when I eat this?”

Something that is considered healthy may not always suit your body.

At the same time, having difficulty digesting lactose does not necessarily mean that you need to completely avoid dairy products.

The important thing is not to apply someone else’s “correct answer” directly to your own body.

It is to understand your body’s responses and make choices that suit you.

At KAMI, we believe that maintaining a healthy body is not only about receiving treatment.

Learning how the body works and understanding daily self-care are also important parts of long-term health.

Our therapists are expected to have professional knowledge about the body, but we also want our clients to develop the ability to understand their own bodies.

Professional body care from your therapist, together with your own knowledge and daily self-care.

By combining these elements, KAMI aims to support not only temporary changes in how your body feels, but also your ability to take care of your health in the years ahead.

Today, try asking yourself one simple question:

“After eating the foods I regularly choose, how does my body actually feel?”

That small moment of awareness can be the first step toward understanding your body better.