Common Nutrition Myths, Debunked
In the elevator, online and even at parties, registered dietitian nutritionists (RDNs) get asked food-related questions all the time. Many of the questions are on topics read on social media or from water cooler discussions with friends. The gist of many conversations typically begins with statements like, “I read online that this food is bad” or “My friend told me that this is what happens when you eat this food.” RDNs also scroll through social media platforms and see posts and articles disseminating myths about food and nutrition, often by non-credentialed individuals who deem themselves experts.
We asked 17 RDNs from around the country the nutrition myth that drives them bonkers — and to debunk it once and for all.
Myth: Eating after 7 p.m. makes you gain weight.
RDNs get asked this question a lot and it’s a myth that drives Leslie Bonci, MPH, RDN, CSSD, LDN, FAND owner of Active Eating Advice crazy! “There are so many variables to consider here,” said Bonci, citing this study. If you have already consumed your calorie allotment for the day and continue to eat after 7 p.m. then yes, you’re consuming excess calories. “However, there are many countries in the world where the standard dinner time is 9 p.m. or later,” explains Bonci. What’s more important are the types of foods and quantities you choose rather than what time you eat them.
Myth: You shouldn’t eat fruit because it’s too high in sugar.
According to New York-based registered dietitian Katherine Brooking MS, RD, this myth seems to remain persistent as high sugar consumption is a problem in the U.S. and whole fruit does contain sugar. However, while fruit contains sugar, “It is naturally occurring sugar,” explains Brooking. The naturally occurring sugar in whole fruits provides energy for the body, as well as fiber and essential nutrients including potassium, vitamin C and folate. Further, “Whole fruit is an important part of a healthy diet, linked to lower rates of heart disease and some cancers,” Brooking says. Added sugar, on the other hand, found in many sugar-sweetened beverages, cakes, cookies and other sweets adds calories and sugar without providing nutritional value.
Myth: You can’t get adequate quality protein on a plant-based diet.
This is a myth that Jackie Newgent, RDN, CDN, chef, private cooking instructor and author of The Plant-Based Diabetes Cookbook hears often. “You can get 100 percent of the amino acids (building blocks of protein) your body needs when following a plant-based eating plan. The fact is plant food contains all 20 amino acids, including all nine essential amino acids,” explains Newgent. You can ultimately get all the amino acids and at the levels your body requires within a plant-based eating style simply by doing three things Newgent recommends: Meet your energy needs; include a variety of foods for differing amino acid profiles; and make smart choices, like regularly enjoying pulses, nuts and seeds.
Myth: You should avoid eating egg yolks.
“Eggs are a nutrient-rich powerhouse, and they are a regular part of my diet,” says Liz Weiss, MS, RDN, food writer and podcast host of Liz’s Healthy Table. Weiss explains, “Nearly half of an egg’s protein and most of its vitamins and minerals are found in the yolks, so tossing them is a big waste of money and good nutrition.” In fact, according to the American Heart Association, eggs can be part of a heart-healthy diet. While it’s true that egg yolks contain cholesterol, research shows that most of the cholesterol in our bodies is made in our livers and not from the cholesterol we eat. “One large egg has 70 calories, six grams of high-quality protein, and nutrients like choline, important for brain health at every life stage, and lutein and zeaxanthin, carotenoids in egg yolks that protect our eyes from blue light,” Weiss continues. Further, eggs are also one of the only regularly eaten foods that naturally contains vitamin D which is an under-consumed nutrient by most Americans. “Eggs are affordable and versatile, and consuming them as part of a healthy diet doesn’t increase heart disease risk. I enjoy them scrambled, hard boiled, and in veggie-filled omelets … and I hope you will too,” Weiss says.
Myth: All ultra-processed foods are bad for you.
“The most common system to categorize processed food lumps many nutritious foods, such as tofu, peanut butter and lactose-free milk, in with less-nutritious choices, such as sugary soda, snack chips and candy,” explains Elizabeth Ward, MS, RDN, co-author of The Menopause Diet Plan. Ward believes that the advice to avoid foods based solely on processing is shortsighted, and research shows that it can actually result in nutrient deficiencies. “A 2022 European Journal of Nutrition review found that excluding ultra-processed grain foods, such as cereal, rice and pasta, would result in lower intakes of iron and several B vitamins,” explains Ward. As such, she suggests choosing foods based on their nutritional merits and not their degree of processing.
Myth: Frozen and canned produce is less nutritious than fresh.
“Eating fruits and vegetables in any form, including canned and frozen, can provide key nutrients like fiber, vitamins, minerals and antioxidants,” says Mandy Enright, MS, RDN, RYT, the FOOD + MOVEMENT Dietitian and worksite wellness specialist. Many people are concerned that the canning or freezing process removes nutrients, leaving canned and frozen produce void of any nutritional value. However, Enright assures us that this couldn’t be further from the truth. “In fact, frozen and canned produce is actually picked at peak ripeness during harvesting, which means that the optimal nutritional value is actually being preserved best during this time,” explains Enright. In fact, freezing or canning not only preserves the nutritional value, but in some cases can even increase the bioavailability of some nutrients, such as lycopene in canned tomatoes. Further, while there can be some small, minimal losses of some nutrients during the canning or freezing process, the truth is these losses are no different than the nutrient losses that occur over time in fresh produce stored at home.
Myth: Soy causes cancer.
Seattle-based registered dietitian nutritionist Ginger Hultin, MS, RDN, CSO owner of Ginger Hultin Nutrition and author of Anti-Inflammatory Diet Meal Prep sets the record straight on this myth. “Evidence strongly supports that soy foods are likely linked to reduced risk of some types of cancer in some populations and that there should not be restrictions in consumption of whole foods soy, including in cancer survivors,” Hultin explains. “Special antioxidants in soy may be the reason for some of the health benefits we see with consumption. I suggest my clients consume soy from tofu, tempeh, miso and unsweetened soymilk.”
Myth: If you want to eat healthy, you should only shop the perimeter of the grocery store.
The idea that healthy foods are only found in the perimeter of the grocery store continues to circulate, despite plenty of advice from nutrition experts urging shoppers not to avoid the range of health-promoting foods found in the inner aisles. According to Malina Malkani, MS, RDN, CDN, owner of Malina Malkani Nutrition and author of Safe and Simple Food Allergy Prevention, “This myth is based on the misconception that the inner aisles contain ‘unhealthy’ foods, and that the only foods that qualify as ‘healthy’ are fresh foods found in the produce, dairy, meat, seafood and other sections that line the outer walls of most grocery stores.” But that couldn’t be further from the truth. Malkani explains that skipping the inner aisles means missing out on a variety of nutrient-rich, satisfying, health-promoting foods (including dried and canned beans, whole grains, pasta, nuts, seeds, nut butters, tomato sauce, olive oil, canned fish, frozen produce and dried fruit) that contribute valuable nutrients to a balanced diet.
Myth: Dairy causes inflammation.
According to Jim White RDN, EX-P, owner of Jim White Fitness and Nutrition Studios, the opposite is actually true! “A strong body of research suggests that dairy foods like milk, cheese and yogurt are not inflammatory but can have anti-inflammatory effects. In fact, a 2019 validated inflammation scoring system found that both high-fat and low-fat dairy foods had anti-inflammatory scores,” explains White, who says dairy foods are nutrient-dense and can certainly be a part of an anti-inflammatory diet.
Myth: MSG causes “Chinese Restaurant Syndrome.”
“Chinese Restaurant Syndrome” is a reported condition that results in symptoms like headaches, palpitations, dizziness after eating Chinese food that was attributed to eating MSG. According to Keith T. Ayoob, EdD, RD, FAND Associate Clinical Professor Emeritus at Albert Einstein College of Medicine Department of Pediatrics and owner of Cut to the Chase Nutrition, “This started from a letter to the editor of a medical journal in 1969, and went viral but was never proven, despite years of research.” In fact, Ayoob explains that it would be impossible for MSG to cause these symptoms because MSG has only two components: sodium, and glutamate, both of which our bodies have in much larger amounts. Sodium is no different from the sodium we get from other foods, and glutamate is a “non-essential” amino acid that our bodies make daily on their own – in far larger amounts than you’d ever get from MSG. This published review provides a summary and states the credible science: MSG does not cause these symptoms and is safe to eat.
Myth: Juicing is the healthiest way to take in your fruits and vegetables.
According to Mascha Davis MPH, RDN, author of Eat Your Vitamins, juicing strips away what is arguably one of the best parts of fruits and vegetables: fiber. “Fiber is an essential component of a healthy gut and digestive tract, feeding the good gut bacteria and helping them (and ultimately, us) to thrive,” explains Davis. “Newer research has also shown that fiber contains additional beneficial compounds, called bioactives, which help with disease prevention.” Further, Davis explains that fiber confers many other benefits, including reducing the risk of heart disease and diabetes, aiding in weight loss and weight management and reducing the risk of depression, among others.
Myth: You need to drink a gallon of water every day.
“Someone’s hydration status is extremely individualized and many need about 64 ounces of water,” says Alyssa Smolen, MS, RDN, CDN, and content creator. Of course staying hydrated is important but most people don’t realize they can over hydrate and this can in turn be potentially harmful. In addition, part of the fluids your body needs can also be taken in by eating fruits, vegetables and other high-water content foods.
Myth: Seed oils are bad for you.
“I see many people believing that seed oils are harmful to health (or even ‘toxic’), but the vast majority of research doesn’t bear this out,” explains nutritionist and health writer Sarah Garone, NDTR, CNC. Garone explains that although oils like rapeseed (a.k.a. canola), vegetable or sunflower seed are commonly used in many processed and ultra-processed foods, it’s not the oils themselves that cause inflammation or other health concerns. If anything, the omega-6 fatty acids in these oils have been shown to reduce inflammation and are even linked with improved cardiovascular health outcomes. Using them in moderation can be an excellent addition to healthy cooking.
Myth: The Keto Diet is healthy.
“The Keto diet continues to dominate diet trends – without good long-term research to back up the many claims,” says Alexandra Caspero, New York Times bestselling chef and registered dietitian at Delish Knowledge. Caspero explains that the Keto diet was developed in 1921 to manage seizures in kids and has a 4:1 ratio of fat to carbohydrates and protein. Despite what you often see online, it’s a high-fat diet, not a high-fat and high-protein diet. In order to meet such macro ratios, proponents will often consume high amounts of fatty, moderate-protein foods like bacon, coconut oil, ghee and egg yolks. “While the keto diet has been shown to promote weight loss within the first six months, the diet also increases levels of ‘bad’ cholesterol – LDL and VLDL, which can increase the risk of cardiovascular disease.”
Myth: Enriched white rice is unhealthy.
“White rice is a staple food for more than half of the world’s population and certainly a staple in my kitchen!” exclaims Christy Wilson, RDN owner of Christy Wilson Nutrition, LLC. Enriched white rice is simple to prepare, has a beautiful fluffy texture, combines perfectly with vegetables, fish and meats, and is easy for people of all ages to tolerate. Wilson recommends looking for rice labeled as “enriched,” indicating that valuable nutrients like folate, thiamine (Vitamin B1) and iron have been added back in after processing.
Myth: Eating carbohydrates causes diabetes.
According to Lisa Andrews, MEd, RD, LD owner of Sound Bites Nutrition, “Research supports the intake of whole-grain carbohydrates in the prevention of diabetes, not the development.” In fact, Andrews says that commonly eaten breakfast foods like oats, whole grain cereal and rye bread can be included as part of a healthy diet to help reduce the risk of diabetes. Including whole grains in place of refined grains improves blood sugar control in individuals with diabetes.
Myth: Eating fat will make you gain weight.
This myth surprises Wendy Bazilian, DrPH, RDN author of the Eat Clean, Stay Lean series and owner of Bazilian’s Health. Bazilian explains, “Research shows that healthy eating patterns linked with effective weight loss and long-term weight management feature increased amounts and increased frequency of fruits, vegetables and plant-sources of fiber and unsaturated fats — at higher levels than most people eat. And in order to reduce overall calorie (energy) intake to succeed with weight loss (if that’s your goal) — without feeling hungry or unsatisfied — replacing some higher-calorie, low-nutrient foods with healthy fats, fiber and water can be key.” When you eat fat, it stimulates hormones in the body that tells you that you’re full. Fats also slow the process of moving food from the stomach to the small intestine which can also contribute to feeling full. Healthy fats that Bazilian recommends include avocados, chia seeds and walnuts.