Here's a surprising statistic: One in 10 millennials are vegan, according to to a report in Nutrition Business Journal. Call it a lifestyle or call it an elimination diet—either way, it's picking up steam due in part to like backers like Beyoncé. (Who doesn't want to be a little more like Queen Bey?!) And even Khloé Kardashian recently claimed that she lost 11 pounds just by cutting cheese and milk from her diet.
Related: Should You Go Vegan Like Beyonce?
Why is veganism going mainstream? Cynthia Radnitz, Ph.D., a professor of psychology at Fairleigh Dickinson University who studies vegetarian diets, says there are many contributing factors. "Increasing interest in adopting a vegan diet has occurred for a variety of reasons including health optimization (weight control, disease prevention and reversal), animal rights/welfare (opposition to killing animals for food, horrible conditions on factory farms), and concern for the environment (realization that animal agriculture contributes to several forms of environmental degradation including deforestation, rising greenhouse gas levels, water pollution, and depletion of sea life)," says Radnitz.
Social media has also spread the word about blogs and other media touting veganism. Many restaurants have added vegan options, and stores are stocking more plant-based substitutes for meat, dairy, and egg products, eliminating some of the roadblocks that used to make vegan diets hard to stick to, she says.
Ditching dairy for environmental or animal welfare reasons is totally a personal choice, but going vegan as a way to lose weight is a little more complicated. Just because it worked for Khloé doesn't necessarily mean it'll have the same effect on you.
"The difficulty of course with celebrity endorsements is they haven't been assessed by science, and there's no science to support that their strategy would work reproducibly in a wide variety of people," says Susan Barr, Ph.D., R.D., a professor of nutrition at the University of British Columbia. "But, on the other hand, you can never argue with what an individual says and feels."
Just like fat was feared in the '90s, dairy may be going through a period of undue criticism, says Paige Smathers, R.D.N., a dietitian based near Salt Lake City. "We kind of go through these cycles of what we vilify, and I think this is part of the ebb and flow of nutrition and how people like to vilify things," says Smathers. "Right now it's dairy, and it's pretty unfounded."
One thing you may have heard is that milk contains hormones. Some cows are given bovine somatotropins—growth hormones that increase milk production. However, only a minuscule amount makes it into milk, and your gastric juices break it down, says Richard Raymond, M.D., a food safety and public health consultant based in Colorado. And although milk contains some estrogen, the concentration is too low to be a concern, he says.
Consider how dairy may or may not fit into your diet:
Dairy is rich in bone-building nutrients.
You've heard it a million times: Calcium is good for your bones. However, this mineral's skeleton-preserving properties are particularly crucial when you're trying to drop pounds. "As you lose weight, you can also lose bone," says Barr. "If you have sufficient calcium intake during weight loss, that can reduce the impact on bone density." A cup of 1% milk provides 314 milligrams of calcium—nearly a third of what you need in a day. Sure, there are other sources of calcium, but they often aren't as concentrated. "You do get calcium from broccoli or kale, but you'd need to eat quite a heroic amount of broccoli or kale to get the same amount of calcium," says Barr. (Like 13 cups of raw kale pieces—which we don't advise downing all at once.) Plus, milk packs bone-boosting vitamin D, says Smathers. "It's great to get vitamin D with calcium because you're getting fat from the milk, which helps you absorb the fat-soluble vitamin D, and the vitamin D helps you absorb the calcium," she says. Many of us can use more vitamin D anyway: About 42 percent of the population is deficient, according to a study in Nutrition Research.
Dairy may help you stay slim.
Yes, you read that right. "There's actually some pretty good research suggesting that dairy products are actually helpful with weight loss," says Smathers. She recommends two to three servings of dairy products a day—and not the fat-free variety. You know that protein-rich Greek yogurt is a filling snack, and even cheese can be part of a weight-loss diet in reasonable quantities, Smathers says. Take, for instance, a sprinkle of feta on a salad. "It adds that bit of creaminess and deliciousness that makes you feel satisfied and not like you want more and more and more," she says. In fact, in a study published in the International Journal of Obesity, people who ate three servings of dairy a day gained slightly less weight as they aged than those who consumed less. Study author Paul Jacques, D.Sc., director of the Nutritional Epidemiology Program at Tufts University, says more research is needed, but there are a few theories about how this might work. For example: "Calcium intake is believed to be associated with lipogenesis, which is the formation of new lipids in the body," he says. More calcium may equal fewer fat cells.
Dairy can be difficult to digest for some people.
About 30 million Americans are lactose intolerant, which means they develop problems like bloating, gas, and diarrhea when they eat lactose, a sugar found in milk. These symptoms occur because these folks lack the enzyme needed to digest lactose. For lactose-intolerant people, reducing dairy could help them drop inches by reducing the bloat that can lead to a puffy stomach, says Smathers. However, the effects likely wouldn't be drastic, because lactose intolerance doesn't cause weight gain. It's often the opposite: "People with severe maldigestion/malabsorption are actually at risk for weight loss and underweight, because they're not absorbing all the calories in the foods they eat," says Barr. What's more, lactose intolerant people don't always need to totally ditch dairy. Yogurt and hard cheeses contain very little lactose. Some lactose intolerant people can even consume a serving of dairy without symptoms as long as they don't eat it on an empty stomach, says Barr. If you suspect lactose intolerance, your doctor can test you. It's tricky to detect by yourself because the symptoms are similar to the fallout from other conditions like irritable bowel syndrome.
The bottom line? "People should not eliminate any food unless they have really good reasons," says Smathers. "For nutritional reasons, mental health reasons, and also for quality of life. If you're cutting something out, you should really know it's essential and not a guess, because it's potentially setting you up for some difficulties nutritionally and otherwise."