Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In

Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In


Ask the Nutritionist

In-the-Know on GMOs

A step-by-step guide to cutting GMOs from your diet-the healthy way.

Heading out the door? Read this article on the new Outside+ app available now on iOS devices for members! Download the app.

Q: How can I avoid the most common mistakes on a GMO-free diet? -Tim T., Mendocino, Calif.

First, you have to know which foods are genetically modified and which ones aren’t. That’s a problem that I see all the time. Just as people who wanted to avoid gluten had to learn which foods contain obvious-and hidden-sources of gluten before national labeling guidelines were enacted, people who want to sidestep GMOs need to learn the same type of in-depth information. I spell out these details in my recently published book Going Against GMOs. It’s important to learn the nine at-risk crops, plus two other common GM sources, and keep that information as part of your shopping know-how.

Non-GMO Basics

An easy way to remember the nine prevailing GM crops is to remember their initials: 3 Cs, 2 Ss, an A, a P, a Y, and a Z. The GM crops in that order are: Corn, Canola, and Cottonseed; Sugar Beets and Soybeans; Alfalfa; Papaya; and Yellow Squash and Zucchini. Two additional direct GM products are Aspartame (NutraSweet) and rBGH (recombinant bovine growth hormone, which is injected into some dairy cows and found in some milk products).

Once you know the crops that are typically genetically engineered, the next step is to become knowledgeable about what kinds of foods contain those ingredients. Corn appears in countless forms-such as corn syrup, corn oil, and cornstarch-in most processed foods, and it is also fed to livestock and poultry used for meat. Soy is found as soybean oil, soy sauce, tofu, and soy protein, and it’s also given as feed to animals. Sugar beets show up as beet sugar on labels, and that ingredient is hidden in many foods that contain “sugar.”

To steer clear of GMOs, avoid foods that contain these ingredients in their many forms, and eat foods that are labeled Non-GMO Project Verified or USDA Organic.

Beyond Non-GMO

There’s another kind of “mistake” people make when they’re trying to avoid GMOs: selecting non-GMO junk foods-or food allergens-that get them into other types of health trouble. For example, many people seek out foods made with non-GMO sugar. You may think of these foods as “safe” and end up eating them with abandon. What people forget-or may not know-is that overconsumption of sugar, whether GMO or not, derails health over time: It suppresses immune function; feeds yeast and harmful bacteria in the gut; and is regarded as an independent risk factor in cardiovascular disease, type 2 diabetes, liver cirrhosis, and dementia. Other non-GMO foods, such as refined vegetable oils and trans-fats, also promote disease in ways that have nothing to do with GMOs.

It’s important to understand that avoiding GMOs is only one part of a healthy eating plan. To promote optimal health, in addition to avoiding GMOs, I recommend ditching sugar and artificial sweeteners, whether GMO or not; being wary of corn, soy, and milk products, whether GMO or not; avoiding wheat and gluten and eating more non-starchy vegetables; steering clear of refined vegetable oils and trans-fats; and avoiding exposure to chemicals, including pesticides and food additives.

Following these guidelines while avoiding GMOs isn’t easy. But these are the recommendations I gave my clients long before GMOs became such a huge and troublesome issue. They’re just as important to follow now that so many of us are waking up to the risks associated with GM foods.

Going Against GMOs Giveaway! Enter to win a copy of this book! Two different ways to enter: (1.) Email your name and address to with “GMOs” in the subject line. (2.) Sign up to get Melissa Diane Smith’s Against the Grain Nutrition e-newsletter at You can enter both ways or just one way during the month of March. One entrant will be chosen at random in each giveaway on April 1.

Going Against GMOs