Miley Cyrus is looking leaner than ever these days, fueling mass speculation of an eating disorder. On Monday, she took to Twitter to defend her slim physique: "For everyone calling me anorexic, I have a gluten and lactose allergy. It's not about weight, it's about health. Gluten is crapppp anyway!"
While Cyrus' weight loss may be due to a legitimate food allergy, scads of other celebrities and non-famous folks alike are adopting a gluten-free diet—for weight reasons, not health. "It's definitely trendy now. Everyone is talking about it," says Elisabetta Politi, nutrition director at the Duke Diet and Fitness Center in Durham, N.C. And the food industry is apparently cashing in on the trend, too: By 2015, sales of gluten-free foods and beverages are expected to hit $5 billion, according to Packaged Facts, a market research firm. "I see the positive side of being more aware of gluten and trying not to overdo it," says Politi, "but I don't think it's a good way to lose weight."
Gluten is a protein found in wheat, barley, and rye, as well as many common food additives. It gives dough elasticity and baked goods their chewiness. (It's found in pizza, beer, burgers, and pancakes, for example.) Those who have celiac disease—caused by an overactive immune response to gluten in the small intestine—are encouraged to go gluten-free to avoid digestive symptoms like pain and diarrhea, and even permanent intestinal damage or malnutrition. There's no cure or medication other than a gluten-free diet. About 1 percent of the population suffers from celiac and about 10 percent have a less specific sensitivity, according to the Mayo Clinic.
But there's no hard evidence that a gluten-free diet is appropriate for weight loss or is any more effective at whittling waistlines than other diet plans. Most experts recommend it only for those with celiac disease or gluten intolerance, says David Katz, founding director of the Yale-Griffin Prevention Research Center.
Still, cutting out gluten can lead to weight loss, since the plan forces dieters to shun high-calorie refined carbohydrates. "Tell anyone to cut down on bread and pasta, and they're likely going to drop calories and lose weight," Politi says. But gluten-free is no weight-loss panacea, either. "If you're going down the grocery aisle grabbing gluten-free cookies and pasta and bread, you probably won't be as successful." A gluten-free brownie is still a brownie. Often, these products are packed with saturated fat, cholesterol, and sugar to improve taste.
Another downside: Gluten-free dieters often don't get enough iron, calcium, zinc, and B vitamins like folate and niacin. "They're missing out on lots of nutrients, as well as fiber," says Katherine Tallmadge, a registered dietitian and author of Diet Simple: 192 Mental Tricks, Substitutions, Habits and Inspirations. That's because it can be difficult to shape a well-rounded menu with such strict rules. An optimal gluten-free menu would include fruits and veggies, brown rice, seeds, nuts, meat, fish, eggs, and milk products. But it's typical for dieters to load up on not-so-healthy gluten-free offerings. If weight loss is your only reason for going gluten-free, says Tallmadge: "It's a terrible idea."
Weight-loss aside, Cyrus claims she feels better going gluten-free, and encouraged her 5.4 million Twitter followers to follow suit: "Everyone should try no gluten for a week! The change in your skin, phyisical [sic] and mental health is amazing! U won't go back!"
Counters Tallmadge: "Most people try it because they feel tired, bloated, or depressed. But we all feel that way from time to time, and it's no reason to rush into a gluten-free diet."