7 Nutritionists Reveal the Worst Nutrition Advice They Ever Heard

Don’t eat fruit?!

Loading the player...

The internet has no shortage of nutrition advice—and let’s be honest, plenty of it is not worth repeating. Eating nothing but watermelon all day? Sip lemonade and cayenne to lose weight? Try a “taco cleanse?” Unfortunately, iffy diet trends can spread like high school locker room gossip and become stubborn parts of food culture. So, HealthiNation asked seven nutritionists for the most outrageous, unproven, or even harmful advice they’ve ever heard, and what to do instead.

Bad advice: “Don’t eat anything white or brown.”

Adding color to your meals is a great way to get a variety of important nutrients from your diet, according to the American Heart Association. Sure, eating the rainbow is optimal—but that doesn’t mean white and brown foods are off-limits.  

In fact, “lots of white foods are actually nutritious—like onions, garlic, and leeks, for example,” explains Jennifer Fitzgibbon, MS, RDN, CSO, CDN, and registered oncology dietitian at Stony Brook Cancer Center. Fitzgibbon also cites bananas, white peaches, cauliflower, mushrooms, and ginger as some examples of good-for-you beige foods.

If your meals are consistently white and brown all over (and that’s mostly due to piles of rice or pasta on your plate) you might want to reassess and see if you can add more color—but that doesn’t mean all white and brown foods need to go.

Bad advice: “Soy is unhealthy or dangerous.”

Soy contains natural forms of estrogen, which has led some people to worry that it can affect may affect hormonal balance and cause breast cancer in women or cause men to develop female characteristics. Turns out, it was a lot of hogwash. “Many plants we eat contain plant-estrogens (or phytoestrogens),” says Ginger Hultin, MS, RDN, CSO, and Arivale coach. “We eat them every day and they are not the same as human estrogen. In fact, they have an entirely different chemical structure.”

The American Cancer Society actually says eating traditional soy foods like tofu, tempeh, miso, and edamame may lower the risk of breast cancer, as well as prostate and endometrial cancers. Soy’s benefits go beyond preventing cancer: “Studies link them to positive outcomes for bone and cardiovascular health,” says Hultin. “It is safe and likely beneficial to eat soy foods every day.”

Bad advice: “Don’t eat fruit because it’s high in sugar.”

Wait, what?!

It’s true, fruit is high in a certain type of naturally occuring sugar known as fructose, but fruit’s high-fiber content means it generally has a low glycemic index, according to the American Diabetes Association. That means your body digests fruit slowly compared with other foods, so they don’t cause the same blood sugar spikes as, say, a doughnut or iced mocha.

“Fruits are nutrient-rich foods that are high in vitamins, minerals, and fiber,” says Jacinda Roach, PhD, RD. “If consumed in the correct portions, they can actually enhance a well-balanced diet.”

Bad advice: “A calorie is a calorie.”

The quality of your calories are just as important as the quantity. Using your calorie allowance on poor-quality foods means you’re missing the opportunity to nourish your muscles, organs, and bones with the nutrients they need for optimal health. Even if you’re able to maintain your ideal weight by eating a 1,600-calorie diet of mostly fast food, you might develop other health problems over time

“While the numerical values may be the same, little else is the same when it comes to the calories between an avocado and a cookie,” says Candice Seti, PsyD, CPT, CNC. “Sugary foods, highly processed foods, and [even] those low in calories [may] trigger inflammatory reactions in the body, promote cravings, and deprive the body of much-needed macronutrients and micronutrients.”

Bad advice: “Don’t eat fats.”

This bad advice is like a game of telephone dating back to the 1980 Dietary Guidelines from the U.S. Department of Agriculture and the U.S. Department of Health and Human Services. They advised reducing meat and saturated fat consumption; over time, this advice got morphed and misinterpreted, and the low-fat diet craze was born.

But monounsaturated and polyunsaturated fats are an essential component of a healthy diet. “Dietary fat in its natural form actually improves health and reduces inflammation,” says Keith Kantor, nutritionist and CEO of Nutritional Addiction Mitigation Eating and Drinking. “Fat helps improve your ability to regulate your appetite [and] keeps you full for a longer period of time, resulting in fewer cravings.” Here are sources of healthy fats to include in your diet.

Bad advice: “Carbs are bad.”

Just like with #5, it’s never a good idea to cut out an entire macronutrient from your diet. Carbs may be the main nutrient in treats like croissants, cupcakes, and apple pie, but that doesn’t mean all carbs are empty calories. (Here’s more on the difference between complex and simple carbs.)

“Carbohydrates are your body’s first source of fuel used for energy,” says Carrie Moody, RDN and owner of FitBalance Nutrition. “Your body depends on healthy, complex carbs to function properly.” In other words, limit your simple carbs (sorry, pancakes), but enjoy veggies, beans, and whole grains every day.

Bad advice: “Restrict two days a week; eat whatever you want the other days.”

Some people swear by cheat days to help them maintain their diet. However, a 2016 study of 2,886 people who had maintained weight loss for more than five years found that those who followed a consistent diet—no cheat days—were less likely to regain their weight.  

There’s a scientific explanation for this phenomenon: “What happens when people starve themselves for two days? They engage in binge-eating behavior for the rest of the five days of the week,” explains Mindy Lu, MS, CN, LMHCA, and owner of Sunrise Nutrition. “It totally messes up people’s metabolisms.”

You’re better off eating a consistent and substantial diet (with high-quality calories). If you’re not sure how many calories to consume on a daily basis, talk to a doc to see what’s right for you.