How To Go On A Dairy-Free Diet—And 6 Things That Could Happen When You Do

Thinking about eliminating milk, cheese, butter, and other dairy products from your diet? You're not alone. Whether or not to give up dairy—and how to do it—is "one of the top questions I'm asked these days," says Cynthia Sass, MPH, RD, Health's contributing nutrition editor.

One possible reason why so many people are ditching dairy? It's gotten the A-list stamp of approval: Jessica Biel has said she "just feels better" when she doesn't eat dairy, gluten, or wheat; Australian actress Margot Robbie told ELLE UK she avoids it when filming a movie because she thinks it causes breakouts. And earlier this year, Khloe Kardashian told Health she dropped 11 pounds after just two weeks sans dairy. "If I want to lose weight quickly, dairy-free is the way to go," she said.

But can a dairy-free diet really help you lose weight, get clearer skin, and generally feel better? The short answer is that it's different for everyone. "Some people are more sensitive to dairy than others," Sass says, adding that the effects of giving it up can vary from person to person.

But experts stress that quitting dairy is not something to be done spontaneously or without cause. "You don't need to eliminate an entire food group unless there's a legitimate reason," says Keri Gans, RDN, a nutritionist based in New York City.

That said, if you do decide to give up dairy, here's exactly what you're giving up, and six side effects you might experience.

If you're full-on quitting dairy, here's exactly what you can't eat:

• buttermilk
• baked goods that contain milk like cake and muffins
• cheese, including cottage and ricotta cheeses
• condensed milk
• ice cream
• milk
• sherbert
• sour cream
• yogurt
• ice cream
• sour cream

If you're fully committing to quitting lactose as well, watch out for the follow lactose-derived ingredients like:

• butter
• casein, casein hydrolysate, and caseinates
• cream, including whipped cream
• curds
• diacetyl
• dry milk solids
• dry milk powder
• ghee
• kefir
• lactalbumin
• lactoferrin
• lactulose
• non-fat dry milk
• milk byproducts
• nougat
• recaldent
• rennet

Not all hope (or deliciousness) is lost if you're quitting dairy. Consider adding these alternatives to your dairy-free diet plan:

• alternative milk like almond, oat, and soy milk
• eggs
• gelatin desserts and candies
• lactose-free margarine
• non-dairy ice cream made with cashew milk, coconut milk, and more
• dark chocolate
• soy and tofu products

Of course you can continue eating wheat, meat, seafood, fruits, and veggies, with some dairy-free stipulations.

Before you swap out your 1% for almond milk, it's important to remember that dairy products can be part of a healthy diet. After all, there's a reason why the USDA recommends adults have three cups of dairy per day; milk, cheese, and yogurt are rich sources of vitamin D, protein, and calcium, a critical nutrient for bone health. "It's important to know how to replace them [if you give up dairy]," Sass says.

If you've decided to eliminate dairy, work with a nutritionist to create a diet plan that still includes plenty of these nutrients. "It's not to say that someone who gives up dairy can't get enough vitamin D and calcium, but it's not as easy," says Gans.

Dark leafy veggies like kale and collard greens, and fatty fish like sardines and canned salmon are good non-dairy calcium sources. Certain brands of plant-based milk and orange juice are also fortified with calcium and vitamin D, Sass notes, although "they're low in protein, so you may need to bump up your intake of foods like eggs, pulses, or salmon to maintain your total protein intake."

If you've eliminated dairy and are having trouble finding calcium and vitamin D alternatives that you enjoy, meet with a nutritionist to discuss whether or not you should start taking a supplement.

Wanting to lose weight is often cited as a main motivation to cut out dairy, and Sass acknowledges that doing so may help you shed pounds. "I have had clients reduce body fat after giving up dairy," she says.

An important caveat, though: Weight loss after eliminating dairy "is often due to how they consumed it [before], how much, and in what form," Sass explains. If pizza, mac and cheese, and grilled cheese sandwiches were your go-to meals, and you replaced them with lean proteins, whole grains, and fresh produce, then yes—you'd probably see the numbers on the scale drop.

"It's not dairy itself, it's the way it's being consumed," says Gans. In fact, research suggests that full-fat dairy in particular may actually aid weight loss. In a large 2016 study in the American Journal of Nutrition, researchers found that women who consumed higher quantities of high-fat dairy products had an 8% lower risk of being overweight or obese. One possible explanation: Full-fat dairy contains more calories, which may keep you feeling satiated for longer—and less likely to reach for known weight-gain culprits like sugar and refined carbs.

"When people inquire about giving up dairy, it's usually because they're feeling bloated," says Gans, adding that the culprit is almost always lactose intolerance. People with this condition can experience bloating and gas, plus severe stomach pain, diarrhea, and cramps when they consume dairy products. The reason: lactose intolerant folks don't produce enough lactase, an enzyme that's important for breaking down a type of sugar called lactase found in milk products.

However, "not everybody with lactose intolerance needs to 100% remove dairy from their diet," Gans says. Cutting back on your overall intake, or consuming dairy products along with other foods (such as cereal with milk instead of ice cream by itself) may be enough to ease symptoms.

If you have a condition that damages the digestive tract, such as Crohn's disease or celiac disease, you may also get relief from inflammatory bowel disease (IBD)–like symptoms when you cut back on dairy.

Margot Robbie may swear going dairy-free helps her fight blemishes, but the relationship between diet and acne is an ongoing source of debate among dermatologists. Research stretching back to the 1940s suggests at most a weak link between dairy consumption and breakouts. However, some experts believe the hormones in milk products could play a role in exacerbating hormonal acne, and many people do report clearer complexions when they give up these foods.

The American Academy of Dermatology recommends noting any food triggers that seem to aggravate skin, and cutting back with the help of a nutritionist to make sure you're still eating a balanced diet.

If you're breastfeeding, you should know about Cow's Milk Protein Intolerance (CMPI), which  affects up to 3 percent of infants according to a 2005 review in Pediatric Nursing, and can result in colic-like symptoms like wheezing, vomiting, diarrhea, constipation, a rash, eczema and/or a blocked nose. It is not the same as lactose intolerance you'd usually see in adults and children. As a course of treatment, going dairy-free as a breastfeeding mother would be necessary for infants already diagnosed according to a 2007 review in Archives of Disease in Childhood.

Usually CMPI goes away within the first 12 months, but if you're worried your baby may have CMPI, talk to your pediatrician, who may refer you to a nutritionist to help you establish the best dairy-free breastfeeding diet plan for you and your baby.

There's no scientific evidence to back up claims that dairy aggravates skin conditions. That said, some people with eczema and psoriasis report fewer symptoms after they cut back or completely eliminate dairy.

In general, when skin is acting up, a nutritionist may recommend an elimination diet to help pinpoint the offender. Dairy is considered one of the most common food allergens (along with wheat, eggs, soy, fish, shellfish, tree nuts, and peanuts), and is usually one of the groups excluded in such a diet. After a few weeks, food groups are added back to see which one is triggering inflammation.

The bottom line: Cutting out dairy isn't a guaranteed fix for those with psoriasis and eczema. But if you're experiencing a sudden flare of symptoms, it may be worth trying an elimination diet to find out if a particular food is to blame.