Lactose Intolerance Diet: What to Eat and Avoid

Quick answer

Most people tolerate small amounts; hard cheese and yoghurt are often fine; lactose-free milk and calcium-rich swaps fill the gaps

Lactose intolerance is caused by low levels of lactase, the enzyme that breaks down lactose. It is very common worldwide, especially in adults of Asian, African and South American heritage, and can also follow gut infections or coeliac disease. Symptoms such as bloating, wind, stomach cramps and diarrhoea usually appear 30 minutes to two hours after eating dairy. A review in Gut noted that most people with lactose malabsorption can tolerate up to about 12 g of lactose, roughly a glass of milk, especially with a meal. Hard cheeses and butter contain very little lactose, and yoghurt with live cultures is often well tolerated. Lactose-free milk, lactase enzyme supplements and calcium-rich alternatives help maintain a balanced diet. Avoiding dairy completely can reduce calcium and vitamin D intake.

Important. See a doctor if you have symptoms such as weight loss, blood in your stools, persistent diarrhoea, anaemia or symptoms that started suddenly in adulthood, as other conditions such as coeliac disease or inflammatory bowel disease need to be ruled out. Do not confuse lactose intolerance with cow’s milk allergy, which can cause hives, swelling or breathing problems.

What is lactose intolerance?

Lactose is a sugar found in milk and dairy products. In the small intestine, the enzyme lactase splits it into glucose and galactose so it can be absorbed. When lactase levels are low, undigested lactose reaches the large intestine, where bacteria ferment it, producing gas and drawing in water. This causes bloating, wind, cramps and diarrhoea. Many people naturally produce less lactase after childhood. The NHS notes that symptoms vary from mild to severe depending on how much lactose is eaten and how much lactase the body makes.

How much lactose can you tolerate?

Most people with lactose intolerance can manage some lactose. A review of lactose malabsorption found that many adults tolerate up to about 12 g of lactose in one sitting, the amount in a glass of milk, with few or no symptoms, especially when taken with food. Spreading dairy through the day, choosing low-lactose foods and having dairy with meals all help. Tolerance can vary from person to person and day to day. Another review noted that complete dairy avoidance is often unnecessary and can lead to low calcium intake.

Approximate lactose content of common foods

Milk (250 ml): about 12 g.
Natural yoghurt (150 g): about 6–8 g, often better tolerated due to live cultures.
Ice cream (1 scoop): about 3–6 g.
Cottage cheese (100 g): about 3 g.
Soft cheeses such as ricotta: moderate amounts.
Hard cheeses such as cheddar, parmesan and Swiss (30 g): under 0.5 g.
Butter (1 teaspoon): trace amounts.
Lactose-free milk and yoghurt: almost none.

Foods you can usually eat

Hard and aged cheeses.
Butter in normal amounts.
Yoghurt and kefir with live cultures (try small portions).
Lactose-free milk, yoghurt and cheese.
Plant drinks fortified with calcium: soy, oat, almond.
All meat, fish, eggs, grains, fruit, vegetables, nuts and seeds.

Foods to limit or test

Large glasses of milk on their own.
Milkshakes, cream and ice cream.
Soft, fresh cheeses in large amounts.
Condensed and evaporated milk.
Milk-based sauces such as béchamel.
Creamy desserts and milk chocolate.

Hidden sources of lactose

Bread, biscuits, cakes and pancakes.
Breakfast cereals and cereal bars.
Processed meats and sausages.
Ready meals, soups and sauces.
Salad dressings and mayonnaise-based products.
Some medicines and supplements, which contain small amounts usually tolerated.
Check labels for milk, whey, milk solids, milk powder and lactose.

Getting enough calcium and vitamin D

Choose lactose-free dairy or calcium-fortified plant drinks.
Eat calcium-set tofu, tinned fish with bones, almonds and green leafy vegetables.
Include fortified breakfast cereals.
Take a vitamin D supplement in autumn and winter, as generally advised.
Ask a dietitian about calcium supplements if dairy intake is very low.

Lactase supplements and other aids

Lactase enzyme tablets or drops, taken just before dairy, help many people digest lactose. Lactose-free products have the enzyme added during processing. Some research suggests that regular, gradual exposure to dairy may improve tolerance, possibly through changes in gut bacteria. Probiotics have been studied, but the evidence is mixed. Symptoms such as bloating can have many causes; see why am I so bloated.

A sample lactose-smart day

Breakfast: porridge made with lactose-free milk, topped with berries.
Lunch: wholegrain sandwich with cheddar, tomato and salad.
Snack: a small pot of natural yoghurt with live cultures.
Dinner: salmon, rice and vegetables with a small knob of butter.
Drinks: calcium-fortified soy or oat drink if desired.

Diagnosis

Lactose intolerance can be diagnosed by improvement of symptoms when lactose is removed for two weeks and their return when it is reintroduced, or by a hydrogen breath test. Coeliac disease and other gut conditions may need to be excluded, especially if symptoms are severe. More about symptoms is in lactose intolerance symptoms.

Eating out and travelling

Ask whether sauces, soups and mashed potatoes contain milk or cream.
Choose tomato-based sauces over creamy ones.
Carry lactase tablets for meals where dairy is hard to avoid.
Coffee shops usually offer lactose-free or plant milks.
Asian cuisines often use little dairy, while some Indian dishes use cream, yoghurt or ghee; ask if unsure.
Aged cheeses on pizza are usually lower in lactose than fresh mozzarella in large amounts.

Lactose intolerance in children

Primary lactose intolerance is uncommon in babies and young children, and symptoms after milk in infants may be due to cow’s milk allergy, reflux or temporary intolerance after a tummy bug. Do not remove dairy from a child’s diet without medical advice, because milk is an important source of calcium, protein and energy. A doctor or dietitian can recommend suitable alternatives if needed.

Key points to remember

Most people with lactose intolerance tolerate small amounts.
Hard cheese, butter and yoghurt are often fine.
Lactose-free products and lactase tablets help.
Keep calcium and vitamin D intake adequate.

Questions about the lactose intolerance diet

These answers are general information and do not replace an examination or individual medical advice.

Can lactose intolerant people eat cheese?

Hard and aged cheeses contain very little lactose and are usually well tolerated.

Is yoghurt OK for lactose intolerance?

Many people tolerate yoghurt with live cultures, especially in small portions.

Does lactose-free milk have the same nutrients?

Yes. It has the same calcium and protein as regular milk.

Can lactose intolerance go away?

Primary lactose intolerance is usually lifelong, but secondary intolerance after an infection often improves.

Is lactose intolerance the same as a milk allergy?

No. Milk allergy is an immune reaction; lactose intolerance is a digestive problem.

Sources

This guide is for general information and does not replace medical advice. How a problem is diagnosed and treated depends on your examination and medical history. If you think you have an emergency, contact your local emergency services.