For many people, a glass of milk or a scoop of ice cream doesn’t just taste bad-it causes bloating, cramps, gas, or diarrhea. If this sounds familiar, you might have lactose intolerance. It’s not a food allergy. It’s not in your head. It’s your body’s inability to break down lactose, the sugar found in milk and dairy products, because it doesn’t make enough of the enzyme lactase. This isn’t rare. Around 68% of the global population has some level of lactose malabsorption, and in Australia, about 1 in 5 adults experience symptoms. The good news? You don’t have to give up all dairy forever. The key is knowing how to diagnose it properly and managing it in a way that fits your life-not someone else’s checklist.

What’s the difference between lactose malabsorption and lactose intolerance?

Many people confuse these two terms. Lactose malabsorption means your body doesn’t produce enough lactase to digest lactose. That’s the biological fact. Lactose intolerance is when that malabsorption actually causes symptoms-bloating, stomach cramps, diarrhea, or excessive gas. Not everyone with malabsorption has symptoms. In fact, studies show 20-30% of people with a positive breath test can drink a full glass of milk with no issues. That’s why diagnosis isn’t just about running a test. It’s about connecting the dots between what you eat and how your body reacts.

How do doctors actually diagnose lactose intolerance?

There are three main ways, but not all are created equal.

The hydrogen breath test is the gold standard. You drink a solution with 25-50 grams of lactose (about 1-2 cups of milk), then breathe into a tube every 30 minutes for 2-3 hours. If your breath shows more than 20 parts per million (ppm) of hydrogen than your baseline, it means undigested lactose reached your colon and was fermented by bacteria-producing hydrogen gas. This test is 90% accurate at detecting malabsorption. But it’s not perfect. If you have small intestinal bacterial overgrowth (SIBO), which affects about 15% of people, you’ll get a false positive. You also have to fast for 12 hours beforehand and avoid antibiotics for four weeks. That’s not easy for most people.

The lactose tolerance blood test measures your blood sugar after drinking lactose. If your blood glucose doesn’t rise by at least 20 mg/dL, it suggests your body isn’t digesting lactose. But this test is unreliable. About 1 in 5 healthy people get false results because of how fast or slow their stomach empties. Plus, it requires multiple needle sticks. Most doctors don’t use it anymore unless they’re ruling out other conditions.

For kids under 5, doctors use the stool acidity test. Undigested lactose ferments in the gut and makes the stool more acidic. A pH below 5.5 is a sign. It’s simple, non-invasive, and works well for babies and toddlers.

But here’s the truth: the most practical test for most adults is the elimination diet. Cut out all dairy for 2-4 weeks. If your symptoms disappear, then slowly add back small amounts-like a quarter cup of milk or a slice of cheddar cheese-and see what happens. This isn’t just a test. It’s your body telling you what it can handle. A 2023 survey found that 73% of people with diagnosed lactose intolerance could tolerate hard cheeses, yogurt, or small amounts of milk without symptoms. Your tolerance is personal. Don’t let a lab result dictate your diet if your body says otherwise.

Why so many people get misdiagnosed

It’s common. A 2022 survey of 1,200 patients found that 42% were first told they had irritable bowel syndrome (IBS) before being correctly diagnosed with lactose intolerance. The symptoms overlap-bloating, cramping, diarrhea. But the treatments are different. IBS often needs stress management and fiber adjustments. Lactose intolerance needs lactose reduction. Misdiagnosis leads to unnecessary meds, endless doctor visits, and years of discomfort.

And overdiagnosis is just as big a problem. A 2023 JAMA Internal Medicine study found that 35% of people who tested positive on a hydrogen breath test could eat normal dairy portions with no symptoms. That means many people are avoiding dairy unnecessarily. And that’s risky. Dairy is the #1 source of calcium and vitamin D for most people. Cutting it out without replacing those nutrients can lead to weak bones, especially in teens and older adults. One study showed 70% of adolescent calcium intake comes from dairy. If you’re avoiding it, you need to know where else to get it.

How much lactose can you actually tolerate?

You don’t have to go cold turkey. Most adults can handle up to 12 grams of lactose in one sitting-that’s about one cup of milk. If you eat it with a meal, your tolerance can go up to 18 grams. Why? Fat and protein slow down digestion, giving your body more time to absorb what little lactase you have.

Some dairy products are naturally low in lactose:

• Hard cheeses like cheddar, parmesan, and Swiss-almost zero lactose
• Yogurt with live cultures-bacteria eat the lactose as it ferments
• Butter-contains only trace amounts
• Lactose-free milk-lactase enzyme has already been added

Even if you have a positive test, try these first. Many people think they’re intolerant, but they’re just avoiding the wrong dairy products.

What about lactase pills and supplements?

Lactase enzyme supplements-like Lactaid® or Dairy Ease-are a game-changer for many. Taking 3,000-9,000 FCC units right before eating dairy can reduce symptoms by 70-90%. They work best when taken with the first bite of food. Don’t wait until you’re halfway through your meal. And don’t expect them to work on large amounts of ice cream or creamy pasta. They’re not magic. But for a splash of milk in coffee or a small serving of yogurt, they’re reliable.

They’re not a cure. They’re a tool. And they’re not covered by most insurance. A 60-count bottle costs $15-$25. But if you’re eating dairy regularly, it’s cheaper than constant stomach pain and doctor visits.

What should you eat instead?

Getting enough calcium and vitamin D is non-negotiable. Adults need 1,000-1,200 mg of calcium daily. Here’s how to hit that without dairy:

• Fortified plant milks (soy, oat, almond): 300-500 mg per 8 oz serving
• Calcium-set tofu: 250-800 mg per ½ cup (check the label)
• Leafy greens: cooked kale, bok choy, collard greens (broccoli and spinach have calcium too, but it’s harder to absorb)
• Canned sardines or salmon with bones: 300 mg per 3 oz
• Fortified orange juice: 300 mg per cup
• Supplements: if you’re struggling, a daily 500-600 mg calcium supplement with vitamin D helps

Vitamin D is harder to get from food. Sunlight helps, but in places like Adelaide, winter sun isn’t enough. A daily 1,000-2,000 IU supplement is often needed. Talk to your doctor about blood tests to check your levels.

The hidden lactose trap

Lactose isn’t just in milk. It’s in bread, salad dressings, processed meats, protein bars, and even some medications. A 2022 FDA audit found that 20% of products labeled “non-dairy” still contained lactose. Always check the ingredients list. Look for: milk, whey, curds, milk by-products, dry milk solids, lactose, milk sugar. Even “nondairy creamer” can have lactose. It’s not a trick-it’s just how food manufacturing works.

Products labeled “lactose-free” must contain less than 0.01% lactose under new FDA rules (January 2023). That’s a good sign. But “dairy-free” doesn’t mean lactose-free-it just means no milk proteins. Always read the fine print.

What’s new in 2025?

Things are changing fast. The LactoQuik® breath test, approved in 2022, cuts the test time from 3 hours to 45 minutes. That’s huge for busy people. Probiotics like Pendulum LactoSpore® are showing promise in early trials-helping the gut digest lactose without enzymes. And apps like MyLactaseTracker® are now used by 62% of gastroenterology clinics to help patients log what they eat and how they feel. These tools make personalization easier than ever.

Europe has already set official lactose tolerance limits: 12g for adults, 8g for kids 4-8, and 4g for under 4. Australia hasn’t adopted these yet, but they’re a good guide. Don’t assume you’re intolerant just because you’re not dairy-loving. Your tolerance might be higher than you think.

Real talk: what works in real life

One woman in Melbourne, 38, avoided dairy for 5 years after a breath test came back positive. She felt better-but was always tired and her bones hurt. She started adding back small amounts of yogurt and hard cheese. Within 3 months, her energy improved. Her bone density scan showed no loss. She didn’t need supplements anymore.

Another guy in Sydney, 29, used to get bloated after coffee with milk. He tried lactase pills. Worked. He still drinks milk. He just takes a pill. No drama.

It’s not about perfection. It’s about finding your balance. You don’t have to be dairy-free. You just have to be dairy-smart.

What to do next

If you suspect lactose intolerance:

1. Keep a food and symptom diary for 2 weeks. Note what you eat and how you feel 1-4 hours later.
2. Try eliminating all dairy for 14 days. Be strict-no hidden lactose.
3. If symptoms improve, reintroduce one dairy item at a time. Start with yogurt or hard cheese.
4. If symptoms return, try a lactase pill before eating it. See if that helps.
5. If you’re still unsure, ask your doctor about a hydrogen breath test. But only if you’re planning to make big dietary changes.
6. Get your calcium and vitamin D levels checked if you’ve cut out dairy.

Don’t rush to a test. Your body already gave you the answer. You just need to listen.