Junk food is kryptonite for weight loss, and, evidently your gut too, says a new diet book that blasts fast food for staving off slimming, good-for-you bacteria
Piling your plate with fast food will pile on the pounds—that much isn't a surprise. But new research sheds more light on exactly how eating processed food wrecks our bodies, starting with some of our smallest parts: our gut bacteria. Tim Spector, Ph.D., author of The Diet Myth and lead researcher of this new study, found that eating fast food for just one week killed a third of beneficial bacteria in the gut. (Gut bacteria is essential for everything from maintaining a healthy immune system to heart health to being in a good mood.) And as more and more research shows the role that bacteria play in our bodies, this new study has implications not only for our waistlines but our entire health, Spector says. (Read this: 7 Surprising Ways Junk Food Makes You Miserable.)
In his book, Spector shares how he recruited his son to try out eating only fast food for a week—not exactly the most rigorous research, but a study that millions of people are unconsciously doing every day. "Before I started my father's fast food diet, there were about 3,500 bacterial species in my gut, dominated by a type called firmicutes," his son, a genetics student, told The Australian. "Once on the diet, I rapidly lost 1,300 species of bacteria and my gut was dominated by a different group called bacteroidetes. The implication is that the McDonald's diet killed 1,300 of my gut species." (That's not all fast food can do. A High-Fat Diet Can Torped Your Metabolism.)
No one is trying to ban fast food (or say you can never have a treat), but eating a wide variety of mostly healthy foods is the key to good health, Spector writes. "Changes in our gut microbe community, or microbiome, are likely to be responsible for much of the obesity epidemic, and consequences like diabetes, cancer and heart disease," Spector writes. "It is clear that the more diverse your diet, the more diverse your microbes and the better your health at any age."
More scientific research needs to be done studying the link between fast food and the gut microbiome, but many researchers say they aren't surprised by the results. Previous studies have linked eating processed foods with diabetes, depression, multiple types of cancer, a lowered immune system, taking years off your life, and of course, obesity.
"Remember that obesity is the second leading cause of preventable death after smoking. This is the first generation in history in which children will die younger than their parents—due to obesity," says Susan Albers, Ph.D., psychologist at the Cleveland Clinic and author of But I Deserve This Chocolate.
Yet there is also a risk to making something "forbidden fruit," Albers adds. Focus on this mantra instead, she suggests: "Eat food with purpose, on purpose. Pinpoint what function this food has, such as filling hunger or looks fun to eat, and make it part of a healthy meal." As for treats, make sure they're just that—a treat, and not all you eat. (A healthy diet isn't always just about what foods you're choosing. Watch out for these 7 Zero-Calorie Factors That Derail Weight Loss.)