Lots of people think they are lactose intolerant. And as it turns out, most of them are probably right because a vast majority of people over the age of two are legitimately lactose intolerant. Confused? I'll walk you through it. 

First of all, what is lactose?

Christin Urso

Lactose is a naturally occurring disaccharide (a fancy word for two sugars bonded together) made up of glucose and galactose. 

Lactose needs to broken down by the enzyme lactase to be digested. When there isn't enough lactase, a common syndrome known as "lactose intolerance," bacteria in your gut try to ferment it, leading to some uncomfortable symptoms. 

How do I know if I'm lactose intolerant? 

Katherine Baker

First off, how do you feel after drinking milk or eating a bowl of ice cream? Common symptoms include stomach ache, gas, diarrhea, a big, bloated belly, feeling uncomfortably full, abdominal cramps, nausea, vomiting, and in some, constipation. 

Many people complain of discomfort after consuming milk products, and there's a reason why. A vast majority of humans over the age of two are lactose-intolerant.

Natalie Beam

Yup, you read that right. It's more unusual to be lactose-tolerant than lactose-intolerant.

Biologically, humans like all mammals are designed to consume milk from their mothers while they are young. Thus, they're born with quite a bit of lactase, the enzyme that helps you digest it.

But as you get older, your body starts to produce less and less lactase, because, biologically, most mammals stop drinking milk and needing large amounts of lactose beyond infancy. 

Katherine Baker

So once you pass the ripe age of two,  75% of people have way less lactose than you were born with because mother nature decided a long time ago you didn't need it. 

And your heritage may play into your risk: while fewer people of Northern Europeans descent suffer from lactose intolerance, it's extremely common in those of Asian descent. 

Is being lactose intolerant dangerous?

Aakanksha Joshi

Lactose intolerance can cause diarrhea and serious stomach pain, so if you suffer from excessive runny stool, make sure you are hydrated and properly nourished, as diarrhea can make your body miss out on absorbing many of the things it needs.

That said, lactose intolerance is an intolerance, not an allergy, which is an important distinction. People with milk allergies can have life-threatening reactions to even trace amounts of dairy, and lactose-intolerance—while certainly uncomfortable—is not the same thing.

Torey Walsh

Most people who are lactose-intolerant can tolerate up to two servings of milk-products per day (even better if they're spaced out) without too many issues, but everyone is different, and only you know your body best.

Just make sure that if you rely on dairy for calcium and vitamin D, you get these nutrients from other sources, like fortified non-dairy alternatives and cereals, or from certain fruits, vegetables, legumes, and tofu.

What foods have a lot of lactose? 

Amanda Shulman

Well, obviously, milk has quite a bit of lactose. Milk-based beverages, including milkshakes and your beloved frapps, are also high on the lactose list.

Other sources include whipped cream, coffee creamer, ice cream, sherbet, custard, puddings, and creamy soups. Certain cheeses, especially processed cheeses, tend to be higher in lactose, as well.

Paige Marie Rodgers

Some snack products, cheesy crackerschocolates and candies, caramels, sauce mixes, and baked goods may be hiding lactose too, so be sure to read labels carefully if you want to know.

Anything processed with whey, casein (a milk protein), milk-by-product, dry milk, or curds, can also contain milk-derived products.

What can I eat if I'm lactose intolerant?

Katherine Baker

Certain dairy products, including butter, ghee, aged cheeses like Swiss, mozzarella, Parmesan, cheddar and brie, cream cheese, and half and half are lower in lactose. Some people can tolerate yogurt, as the probiotics help some break the sugars down.

When it comes to other products, like milk, yogurt, and ice cream, you can either buy lactose-free or non-dairy versions.

And if you're a diehard dairy fan, try having a Lactaid before going ham on your cheese. Or simply practice moderation, and keep your servings to two or less per day, preferably spaced out.