Five Most Popular Nutrition Myths

By Katherine Brooking, MS, RD

The Internet is like the Wild West when it comes to nutrition information: Anything goes. In fact, the web is rife with false nutrition claims, and it fuels myths that add to consumers’ confusion about what is really healthy and what is not. At best, you can hope there’s a kernel of truth in what you’re reading, but oftentimes, it’s just plain nonsense.

False Beliefs About
Nutrition and Health
That Won’t Go Away

Whether you see something on a popular website or receive an e-mail that sounds like it could be credible, be skeptical! There are a gazillion blogs and websites handing out misinformation, trying to increase viewership, sell products or promote a particular agenda. Many myths start from a single source, and if they go viral, they become like facts.

So, let’s debunk some of the most popular online nutrition myths:

Myth #1: Fasting or “cleansing” will detoxify your body
This is one urban legend that never seems to go away. From celebrities to personal trainers, there’s no shortage of “experts” advocating fasting diets or juice cleansing for the purpose of detoxification. But despite all the hype, there’s no scientific evidence to support that the body is detoxified via fasting or juicing. Although caloric restriction, while not strictly fasting, has been shown in some studies to extend life in rodents, yeast and various insects, it is too early to tell if this will have similar effect in humans.

For most healthy people, occasional short fasting periods or juice diets of a day or less won’t cause harm, other than making you feel hungry and tired. If you really want to do your body a favor, get regular exercise, enough sleep, and eat a healthy, balanced diet.

Myth #2: Organic is always better
The subject of organic produce versus conventionally grown is fraught with controversy. There are many aspects to consider, from the environmental impact to cost. But when it comes to nutritional value, most studies have found that organic and conventionally grown foods are similar. Recent research that analyzed data from hundreds of studies found no consistent differences in vitamin content of organic products, and only one nutrient – phosphorus – was significantly higher in organic compared to conventionally grown produce.

While conventionally grown foods indeed have higher levels of pesticide residue, most fall within allowable safety limits. If you are concerned about pesticides but can’t afford the higher prices for organically grown products, follow the recommendations of Environmental Working Group (EWG), a nonprofit organization that specializes in investigating these issues. Their “Dirty Dozen” list highlights the types of produce that are most susceptible to pesticide residue.

Myth #3: Microwaves leak cancer-causing radiation
Microwaves heat food through electromagnetic radiation, but the type of radiation that is used here is not like the radiation for the treatment of cancer patients or when you get an x-ray. What’s more, the low-level radiation that is used in microwaves is essentially all contained within the microwave, and all microwaves sold in the U.S. must meet strict requirements for emissions. There are no published clinical studies that show that microwave ovens are linked to increased risk for cancers in humans. And studies with rodents have had mixed results. Some studies suggest a link between increased cancer tumor growth with long-term, high-level microwave radiation exposure while others don’t.

What to worry about? Avoid using plastic containers in the microwave that contain BPA, which can release harmful chemicals. Also, since burns are the biggest health hazard, use caution when microwaving food.

Myth #4: Margarine is one molecule away from being plastic
It’s hard to know exactly where this started and why it keeps showing up, but some say it stems from the never-ending ‘butter versus margarine’ debate. Butter lovers like to claim a lot of unsavory things about margarine, including this popular myth. Truth is, margarine (and other soft spreads) is made when liquid vegetable oils undergo the process of hydrogenation (adding hydrogen atoms), which turns the liquid vegetable oil solid at room temperature. While the process is definitely less “natural” than butter, which is made from milk, it doesn’t mean margarine is anything like plastic. The reason why margarines are less likely to spoil is because vegetable oils are more shelf-stable and don’t go rancid as quickly as dairy products that must be kept refrigerated.

In the past, margarines did get a bad rap for containing transfats, but most brands have eliminated this harmful ingredient from their products. While the calories of butter and margarine are the same, margarine has significantly less saturated fat than butter and they is cholesterol-free. Margarine and soft spreads have a role for many individuals who try to meet the American Heart Association’s guidelines for limiting saturated fat to no more than 7 percent of total calories, or about 15 grams per 2,000-calorie diet. According to the U.S. Department of Agriculture’s (USDA) nutrient database, a tablespoon of butter has 7 grams of saturated fat, compared to 2 grams in a soft spread.

Myth #5: Some foods have “negative” calories
When something sounds too good to be true, it probably is. A “negative calorie food” may sound great, but unfortunately there is no such thing. The myth of negative calories stems from the notion that some foods will burn more calories than they provide. The faulty logic of this rests on the idea that the thermic effect of food (TEF), that is the amount of energy required to digest food, can give certain foods less-than-zero calories. Celery, apples, and limes are among those touted to be such negative calorie foods. But sadly, there are no negative calorie foods. The TEF generally ranges from 10 percent to 20 percent of the calories in a specific food. For instance, a celery stalk has 7 calories. Even if we assume a 20 percent TEF, that still means your left with about 5.5 calories. Sorry.

Katherine Brooking, MS, RD is a Registered Dietitian, writer and expert contributor to numerous television programs. She has appeared on The TODAY Show, Live with Regis & Kelly, The Early Show on CBS, Good Morning America Health, and many others. She covers health and wellness topics in SELF Magazine, The Washington Post, The New York Times and New York Daily News. For more information go to

The articles written by guest contributors are the sole responsibility of the individual writers in terms of factual accuracy and opinion and do not necessarily reflect the views of the publisher of this blog.

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