7 Harmful Diet Lies You Probably Believe


As a culture, we go through phases with our diet preferences — low-fat gave way to low-carb, dairy-free begat gluten-free, and eggs (poor eggs) are either omega-rich wunderkinds or insidious cholesterol bombs depending on the current political climate and whether or not Mercury’s in retrograde. Yet, there are some out-there diet myths that we simply can’t seem to shake.

Over the course of The Anti-Diet Project, I’ve struggled to dislodge these false beliefs from my own diet-addled brain, but it’s not easy. When I’ve believed for 10 years that a potato is four points, it’s really hard to see it as a potato again. I still struggle with eating dinner, even when I’m hungry, and I’m fairly convinced it’ll take years of couples counseling for me to ever trust bananas again. We’ll get there one day, bananas. 

Considering that I’m clearly bonkers when it comes to food, it helps to have a professional on hand. I enlisted Theresa Kinsella, MS, RD, CDN to take on some of the diet myths that we’re particularly stuck on. Some of them are problems for me, while others seem to be bugaboos for pretty much everyone. Some seem to be obviously bunk, while I fully expected her to come back with, “Well, that one’s kind of true,” about others. Nope. Turns out, when it comes to the “rules” of eating right, we are almost always ridiculously wrong. 

Note: I’m sure that some of the following might not jibe with your current belief system around food. (For the gluten topic alone, I expect a fair amount of tomato-throwing.) I’m not here to convert anyone, nor am I a nutrition professional — but Theresa is. I hope that even if you disagree with, or don’t believe in, any of these statements, you’ll take it upon yourself to do your own research or reach out to your own medical or nutritional pros. We good?


Myth #1 You shouldn’t eat dinner (or anything else) after 7 p.m. 

“There is no universal time that everyone should stop eating,” says Kinsella. “People get up at different times, go to sleep at different times, and eat at different times. Many countries eat dinner later than Americans but their populations weigh less than Americans do. Unless someone has an eating disorder and needs to eat at regular intervals to establish normalized hunger cues, or someone has a self-care reason for eating (like they’ll soon be stuck in a meeting without access to food), it is more important for people to be connected to their internal hunger cues than to be eating based on an external influence, like the clock.”

What’s even more curious is how this diet myth originated. Kinsella wonders if the don’t-eat-at-night rule may have more to do with how we regulate our earlier meals while dieting. “Some people get in bad cycles of skipping breakfast and then overeating at night,” she says. Furthermore, it’s often not about the time we eat but how we’re eating. “Sometimes, people find themselves late-night snacking out of habit while they’re watching TV. Both these patterns should be addressed simply because they aren’t self-care behaviors. But, non-hunger mindless snacking at 9 a.m. would be just as much of an issue as [it is at] 9 p.m.”


Myth #2 Your body doesn’t need carbohydrates. Carbs make you fat. 

This line of thinking is central to quite a few diet programs, but Kinsella puts it right to bed. “With the exception of specialized diets for medical necessity, if someone isn’t eating carbohydrates, they aren’t functioning at their optimal level,” she says. “The brain alone uses 130 grams of carbohydrates per day. Carbohydrates are also necessary for serotonin production.”

She adds that the maligned molecules are even more important if you engage in even moderate exercise. “Carbohydrates are the main source of energy for exercise and many people do not feel good when exercising without them. Since exercise is an essential component of self-care and health, eliminating carbohydrates can be detrimental to overall health.”

Again, no one’s arguing that you need more Wonder Bread in your life, but “whole grains, beans, fruit, and vegetables all contain carbohydrates and are excellent sources of fiber. For this reason, many people on low-carb diets experience an unwanted side effect: constipation.” We’ve all been there. Let’s not go there again.


Myth #3 Paleo is the ideal diet, because we were all once Paleolithic people.

This one particularly irks me. It’s at once so attractive to the dieter (“Of course! Ancient man didn’t have spaghetti, so I shouldn’t, either!”) and so ridiculous (Ancient man didn’t have lentils, and therefore lentils are bad for you?). We also need to acknowledge that we don’tlive like ancient man. Consider, for example, that modern produce bearslittle resemblance to its Paleolithic ancestors. And, hunter-gatherer dietsvaried drastically depending upon where the population lived. Lastly, when is the last time you actively pursued your steak before eating it? 

Back me up, Theresa:

“The Paleo Diet is based on eating food that can be hunted, fished, or gathered, such as meat, fish, shellfish, poultry, eggs, veggies, roots, and fruit, like berries. It does not include grains, dairy, beans, salt, and sugar. Whole grains, dairy, and beans are nutrient-rich foods. By eliminating them, you could be setting yourself up for a deficiency or eliminating nutrients that help prevent disease.” 

No matter how healthy we aim to be, most of us will not continue an eating program if it doesn’t satisfy us. And, Kinsella warns, “the Paleo Diet certainly doesn’t emphasize enjoying your food. When people don’t enjoy their food, it’s difficult to eat mindfully and it is very difficult to sustain… If we look at the research on losing excess weight, it’s clear that people that include highly enjoyable food are actually more likely to maintain their loss.” In other words, we can put in painstaking dedication and effort to supplement the nutrients that paleo lacks, but the call of the bread or cheese — or even lentils —almost always wins out.


Myth #4: There is such a thing as eating right for your blood type.

“No. There is no scientific evidence to support special diets based on blood type.”

Myth #5: Juicing is healthy and cleansing is necessary.

I think we all know where this is going, but just in case:

“The liver and kidneys are the body’s own detoxification system. They do a fantastic job of continuously removing waste products and toxins without the help of juice. Furthermore, there are some obvious drawbacks of juicing; juices are inadequate in protein, fat, essential fatty acids, and fiber. These nutrients are crucial for satiety and vital components for a balanced meal. The protein factor is particularly crucial here. When protein intake is inadequate, the body catabolizes protein from muscles and organs. Hence, someone on a juice cleanse ends up losing muscle mass — a major contributor to metabolism. They’ll likely end up with a worse body composition in the end.”


Myth #6: Eating fat makes you fat.

“Fat, protein and carbohydrates are all essential,” Kinsella stresses. “There is no universal percentage of each that is right for everyone. Eating past full on a regular basis, non-hunger eating, emotional eating, skipping meals and overeating later in the day — those are the behavior patterns that lead to weight gain. The body has an innate ability to regulate and maintain a healthy, genetically determined weight if we listen to it.

“The brain is 60% fat and we need fat in order to absorb fat-soluble vitamins. According to current research, the healthiest dietary pattern is that of the Mediterranean culture, which emphasizes foods, [like] fruit, vegetables, beans, whole grains, nuts, and olive oil. Approximately 35 to 40% of the calories in that diet come from fat.” 

Healthy weight aside, the Mediterranean diet (like the French paradox) also reflects a population that eats a significantly higher percentage of fat, and yet has a much lower incidence of heart disease and similar illness than the rest of the world. Obviously, that doesn’t mean the secret to good health is BUTTER ON EVERYTHING. You should consider the difference between saturated and unsaturated fat, be aware of your personal cholesterol count, and so forth. But, it does indicate that we are hanging on to some very misguided ideas about the role fat plays in our health. 


#7 Gluten is bad for me and you and everyone, period.

Here’s the part where everyone chases me out of the village with torches. 

Again, there’s no argument against the benefits of eating more healthy, whole foods and less junk. Also, if you’re going gluten free, that probably (hopefully) means you’re getting more veggies on the plate to make up for the lack of grain. More veggies can’t hurt! But, unless you have a medical issue, grains can’t hurt you, either. Celiac is a real disease, and one studyindicates that approximately 5 to 6% of the population is gluten-sensitive. However, research also indicates many who report gluten sensitivity are not actually reacting to gluten, but some other factor in their food (see, for instance, FODMAPs) or, frankly, just believe that they are. 

Says Theresa, “A gluten-free diet is a necessity for people diagnosed with celiac disease. Gluten-free diets are also one of the most popular food trends, but there is no benefit to going gluten-free if it is not medically warranted.”

The gluten-free trend (and, whether or not you really do have celiac or gluten-sensitivity, this is still an undeniable trend) just points to another issue plaguing our culture around food. “Eating healthy” is often just used as a different way to say “dieting.”

“Many people are attracted to the fad as a new way to restrict or lose weight… [But] ‘gluten free’ does not necessarily mean ‘better for you.’ Many gluten-free products are a lot more processed than their whole-grain, gluten-containing counterparts. Corn and rice flours are lower in fiber and have a higher glycemic index. Bottom line: a gluten-free cupcake is not healthier than a cupcake with gluten.” 

The Anti-Diet Project runs on Mondays twice a month. Follow my progress (read: sweaty gym selfies and food that doesn’t come in a 100-calorie pack) on Twitter and Instagram at @mskelseymiller or #antidietproject — and hashtag your own Anti-Diet moments! I love checking in on your journeys (and sweaty faces) too!

Click HERE to read more from Refinery29.


  1. The problem with asking nutrition professionals is you get back what they have been trained in. They are trained to promote the foods that are most profitable to the food industry.
    “the Paleo Diet certainly doesn’t emphasize enjoying your food.”
    I don’t understand this. All paleo eating people I know very much emphasize enjoying their food. That is after they get over their sweets and carbohydrate addictions. A comment_content like that could only come from someone that hasn’t eaten paleo.
    “Whole grains, dairy, and beans are nutrient-rich foods.”
    Actually grains are real lightweights when it comes to nutrition. Because they are low labor to produce, they are extremely profitable. Plus they get government subscomment_IDies to make them even more profitable. So the food industry, and their dietitian mouthpieces, push them. One argument is they have B vitamins. But so do lots of other foods. And without the phytic accomment_ID anti-nutrient.
    Some examples:
    B1 – fish, meat, pistachio nuts, Brazil nuts, dried pecans, raisins, green leafy vegetables.
    B2 – almonds, beef, lamb, oily fish, eggs, pork, mushrooms, spinach.
    B3 – fish, chicken, turkey, pork, liver, mushrooms, avocado.
    B5 – mushrooms, oily fish, avocados, eggs, pork, beef, veal, chicken, turkey, sweet potato.
    B6 – pistachio nuts, fish, turkey, chicken, pork, dried fruit, beef, bananas, avocados, spinach.
    B7 – vegetables, fruits, nuts, meat, fish, eggs.
    B9 – liver, spinach, asparagus, lettuce, avocado, broccoli, tropical fruits.
    B12 – shellfish, liver, fish, crustaceans, beef, eggs.
    Dairy is not needed.
    You can get calcium from other sources. A paleo eater does not need as much calcium. Following the regular diet causes much more calcium loss and less is absorbed. Some examples: (1) Phytic accomment_ID, which is found in the bran of whole grains, interferes with calcium absorption. (2) A diet high in sodium may also interfere with calcium absorption. (3) A lack of Vitamin D. (4) A sedentary life. Note paleo advocates encourage being active. (5) Inadequate magnesium compared to calcium intake. It should be 1:1, as found in vegetables. It is 12:1 in dairy. (6) Sugar has been implicated in upsets to the calcium/phosphorus balance. (7) Phosphoric accomment_ID, as found in soft drinks, interferes with calcium absorption. (8) Coffee reduces inositol levels in the blood. Inositol is a regulating factor in calcium metabolism. (9) Caffeine leaches calcium from bones. (10) Tobacco smoking appears to interfere with bone mineralization. (11) Undiagnosed celiac disease is another cause of calcium depletion of the bones. A paleo eater will be gluten-free and solve this one without knowing it. (12) A diet dominated by accomment_IDic foods will tend to raise blood ph which must be buffered. Grains, especially refined ones, are accomment_IDic. (13) Oxalic accomment_ID (found in beans and a variety of vegetables) tends to inhibit calcium absorption through binding to minerals in the intestinal lumen.
    As for Vitamin D: It is added to milk. You might as well take supplements directly and then you can control the amount consumed.

  2. These days almost everybody is afflicted with one or more diseases of civilization. Some examples: high blood pressure, cardiovascular disease, stroke, cancer, diabetes, obesity, arthritis, osteoporosis, acne, gastrointestinal disease, loss of the gallbladder, depression, migraine headaches, and autoimmune diseases like multiple sclerosis and rheumatocomment_ID arthritis. This is discussed in detail in Staffan Lindeberg’s “Food And Western Disease.” Even people strictly following the recommended diet will have these problems. Following the paleo diet is the best option we have to avocomment_ID these.

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