It’s a fact of life: bloating happens, and sometimes for seemingly no reason. Even if you usually eat a healthy diet, you may suddenly have to deal with a puffy stomach. If you regularly deal with bloating, it’s understandable that you’d want to figure out the culinary culprit.

Some people cut out dairy, and this move can make sense. The Mayo Clinic lists milk and milk products as one of several gas-producing foods that can lead to bloating, noting that avoiding or reducing your intake of it may help decrease that puffed up feeling.

“Even though dairy is one of the healthiest foods you can eat, it can definitely cause gas and bloating for some people,” Karen Ansel, R.D.N., author of Healthy in a Hurry: Simple, Wholesome Recipes for Every Meal of the Day, tells SELF. The main reason why many people bloat up after eating dairy is lactose intolerance, she says.

People frequently assume this is a milk “allergy,” but it’s really a deficiency of an enzyme, called lactase, that breaks down the sugar in milk, Ansel explains. “As a result, lactose, the sugar in milk, travels intact throughout your digestive system, pulling water into your gut, causing gas, bloating, and lots of discomfort,” she says.

But a lactose intolerance can vary wildly from person to person, as can which foods cause issues for them, Alissa Rumsey, M.S., R.D., a spokesperson for the Academy of Nutrition and Dietetics, tells SELF. “Most people with lactose intolerance can still tolerate certain dairy products, like yogurt and hard cheeses, like Parmesan and Swiss, which have a lower lactose content when compared with milk,” she says. “Many people can also have small servings of dairy at a time (like 2 to 4 ounces) without issue.”

However, some people can be incredibly sensitive to dairy, Ansel says, adding that it tends to get worse as people age. “It’s not unusual for a person who was always able to drink milk to develop a little lactose intolerance as they get older,” she says.

But none of this means you should immediately swear off dairy. “In fact, totally scrapping dairy from your diet can make lactose intolerance worse because your body produces digestive enzymes to break down the foods that they are used to digesting on a regular basis,” Ansel says. Basically, if you stop exposing your gut to lactose, it’s going to make less and less lactase. Then, if you do drink milk or have dairy products, it’s going to be very uncomfortable. Also, since dairy is a major food group, cutting it out entirely means you’d lower your intake of several important nutrients, like calcium.

The best way to determine if dairy is causing your bloating is to play human guinea pig. Rumsey recommends cutting way back on dairy for a week or two and seeing if your bloating goes away. If it does, you can slowly start to add some small amounts of dairy back into your diet, starting with low-lactose products, like yogurt and hard cheese. If your symptoms return, you know your threshold for dairy.

“You may find that you can drink small amounts of milk with no problem, but not a large glass,” Ansel says. “Many people also find that they can drink milk with food, like a bowl of cereal, but if they drink it alone on an empty stomach, they become really gassy.” People who are more sensitive may not be able to have cheese at all, or they can have hard cheeses like Parmesan or Swiss cheese, since they have very little lactose, she says.

If you’re cutting back on your dairy intake, it’s important to make sure you get calcium from other sources, like broccoli, kale, okra, collard greens, almonds, and shrimp, Rumsey says. “You can also get calcium from calcium-fortified soy products (soy milk, tofu) and calcium-fortified juices and cereals,” she adds.

Many dairy foods also contain vitamin D, New York-based Jessica Cording, R.D., tells SELF, so it’s also a good idea to get vitamin D-rich foods in your diet, like salmon.

If you’re still bloating after lowering your dairy intake or are having difficulty avoiding it altogether, talk to a doctor or dietitian for help, Cording says. They should be able to steer you in the right direction, give you a breath test to determine if you are, in fact, lactose intolerant, and walk you through a full-on dairy elimination diet if that’s the right choice for you.