5 Healthy Eating Myths

Last October, Reason Magazine's Katherine Mangu-Ward took on 5 myths about healthy eating in the Washington Post. But public health and nutrition are complex subjects with important policy implications, and that means there are without a doubt more than 5 dubious ideas about healthy eating floating around the internet, especially in regards to what it means to eat well. With that in mind, here are yet another 5 myths about healthy eating. 

1. Fast food is unhealthy.

It's an article of faith for most people: if you want to be healthy, don't eat fast food. And the circus commonly referred to as "health reporting" is no doubt responsible for making this myth as popular as it is. But the truth is that there is nothing particularly unhealthy about fast food. Hamburgers, french fries, and soda are widely available today. And whether they're purchased from McDonald's or the local grocery store, those foods are bad for you. 

The key, as pediatrician Joanna Dolgoff explains, is making good choices when you eat out. Following the release of Morgan Spurlock's film Super Size Me, several critics of the documentary illustrated this point by eating fast food diets and improving their health in the process. So before you next eat at a fast food restaurant, look up the nutrition information for the food they serve, which is usually available online. But here's a tip to get you started: avoid refined carbohydrates and sugar; that means fries, milkshakes, and sugary soda. Instead, eat a salad and a hamburger without the bun; and drink water, iced tea, or diet soda. Speaking of which....

2. Diet soda causes weight gain.

Diet soda is a clever invention. It's calorie-free and tastes pretty good compared to the regular version. Nonetheless, scary stories about the drink's effects on weight gain are easy to find online. But there's no reason to think drinking diet soda causes weight gain, because "...the science just isn’t there to back it up,” says University of North Carolina obesity expert Barry Popkin. 

There are several studies often cited in support of the diet soda-weight gain link, two studies involving rats and several observational studies which show that people who drink diet soda tend to eat more and development metabolic syndrome later in life. But for every study that finds an association between the two, there's another that shatters it. Indeed, "For every study that shows there could be a benefit or harm [caused by consuming sugar substitutes], there’s another that shows no 'there' there,” according to David L. Katz, MD, director of Yale's Prevention Research Center.

3. "Insert your favorite bad food here" is the problem

Whether soda, ice cream, or some other regularly demonized food, healthy eating is about more than removing a certain food from your diet. The overall composition of a diet is what's important. You may skip your regular starbucks drink or that appetizer before dinner in an attempt to be health conscious, but if you replace the sugar, carbs, and calories with some other equally terrible food or beverage at a different point in the day, you're no better off.    

4. Saturated fat will kill you.

For most of history, saturated fat has been primary part of the human diet, and for most of that time nobody thought it was unhealthy. But beginning in the 20th century, some researchers began suggesting that saturated fat raises cholesterol, which in turn increases risk for heart disease. The hypothesis first gained traction in the 1950s thanks to the work of a scientist named Ancel Keys. Keys published two studies, commonly known as the six-country and seven-country studies, that found an association between saturated fat consumption and heart disease. The more saturated fat a population consumed, the higher their risk of heart disease. 

What's not as well known, however, is that Keys left out countries that didn't conform to his hypothesis. He had data on 22 countries; had they all been included, the correlation between saturated fat and heart disease would have disappeared. In fact, the lipid hypothesis, as it's now called, was heavily criticized by other experts at the time for this very reason. They argued that there was a stronger relationship between sugar consumption and heart disease, a hypothesis which is finally beginning to garner some attention again. 

5. Whole grains are healthy

Because they are a good source of glucose, which our bodies use for energy, most nutritionists recommend that we eat a lot of whole grains. But too much glucose from carbohydrates, even complex carbohydrates like whole grains, can have all sorts of repercussions, like metabolic syndrome. Furthermore, there is solid evidence which suggests that the human body prefers fat as a primary energy source. 

According to a 2004 paper in Nutrition and Metabolism, societies both past and present have thrived on diets almost entirely devoid of carbohydrates. Over the course of human evolution, in fact, we ate very few carbohydrates, and the little bit of glucose we did utilize was made available through a process called gluconeogenesis. This explains why we have so little storage space for gylcogen (the stored form of glucose), because we don't need much of it. And don't worry about your brain, either. As Dr. Emily Deans points out, high-fat diets are good for the brain.