5 Nutrition Myths We Need to Never Hear Again
Have you noticed how insane the diet culture messaging is this time of year? Turn on the TV or radio or tune into most of what’s being promoted on social media and you’ll hear endless advertisements for weight loss programs and fear-mongering food talk—all giving us the message, either subtly or not so subtly, that we can’t trust ourselves with food or our bodies.
I’m calling a no-go on that one. Which is why I thought it would be particularly helpful to bust some dieting and nutrition myths this week. It’s my way of helping you deck the halls ☃️☃️ with holiday food and body peace.
5 Nutrition Myths You Shouldn’t Believe
Myth #1: Carbs cause weight gain or are somehow bad for you.
Truth: Carbs are your body’s primary source of fuel. In fact, they’re the only source of energy for your brain, red blood cells and nervous system. Without them, your body has to perform what I think of as an expensive workaround to create a molecule known as a ketone body that can cross the blood-brain barrier and keep your brain functioning.
Not only are carbs necessary for your body to function, but if you were to look at a pie chart of the optimal intake of the three macronutrients (carbs, protein, and fat), carbs represent the biggest slice of the pie by far.
Fruits, veggies, whole grains, and other sugars including pasta, rice, white breads, baked goods and more are all primarily carbs. The difference between them is that some are simple, shorter chains of sugars that get broken down more rapidly into energy units for your body. Others are longer chains of sugar that take a bit more time to digest. As a result, they may fill you up for longer periods of time. Some also, of course, contain more nutrients.
But the truth is ALL carbs are broken down into glucose and used or stored as energy for your body. They can all be part of a health-promoting diet.
Carbs don’t automatically equal weight gain (which isn’t inherently bad, anyway). They equal readily available energy.
Myth #2: Weight is a simple calculation of calories in versus calories out.
Truth: Bodies come in a range of shapes and sizes, with some naturally smaller or larger than others. Weight does not equal health and not all weight gain is bad.
Nutrition science has moved well beyond the basic calories in vs. calories out equation. We now know that all sorts of other factors influence a person’s weight set range.
Some of these factors include:
the levels of the stress hormone cortisol in your body
how much sleep you get (due to its impact on cortisol and other hormones, such as ghrelin and leptin, which are the hunger and satiety hormones)
exposure to environmental chemicals that may alter hormone functioning
genetics
your gut microbiome (fun fact: we can each eat the same exact carrot and may absorb slightly different calories from it due to the unique composition of bacteria in our respective guts)
Myth #3: Processed foods are bad for us and we need to eat “clean”.
Truth: Almost all foods are processed in one way or another, including grains, pulses, meat, and milk. Processing food to get it from farm to table is a reality of our modern society. I think what people are really referring to when they talk about having to avoid processed foods is actually what many call “ultra-processed” foods. These are foods that have undergone multiple levels of processing and include additives, preservatives, artificial flavorings, and other substances.
When it comes to “eating clean,” this is one of those nutrition teachings that likely originated from a well-meaning place of wanting to encourage people to eat mostly nutrient-dense whole foods, including fruits, vegetables, nuts, seeds, and grains. Which, of course, are great.
Unfortunately, both messages got co-opted by diet culture and turned into something that’s rigid, extreme, and has all manner of unhelpful moral judgments attached to it. These unhelpful judgments can cause eating guilt and stress, which may negatively influence eating behaviors and damage people’s relationship with food and their bodies.
Your relationship with food is the foundation upon which you nourish yourself, enjoy food and your body, and build healthful habits, so it matters. A lot.
The only foods that aren’t clean are ones you dropped or forgot to wash … and all foods, including ultra-processed ones, can be part of a health-promoting diet. Especially if you eat them with attunement to your hunger and fullness cues and how you want to honor your health and wellbeing.
Myth #4: BMI is an accurate marker of health.
Truth: There are so many flaws with the body mass index (BMI) that I should really do a separate blog explaining them to you. But for now, know this. The BMI formula, originally known as the Quetelet index, was created in the 1830s by a Belgian astronomer and statistician. He crafted the formula because he had an interest in looking at the population and trying to classify the characteristics of the “average man.”
It was never meant to be a health marker, nor was it intended to be used on individuals (remember, he was looking at a population). BMI also doesn’t account for differences between sexes, diverse populations, or for differences in bone structure, muscle mass, or distribution of fat.
There’s more. The ranges associated with various BMI classifications (those stigmatizing “underweight, normal weight, obese,” etc. labels) were lowered by about 5 points in 1998 by the National Institutes of Health. They wanted to bring the US numbers more in line with World Health Organization (WHO) recommendations.
The result was that, literally overnight, 30 million Americans who had previously been considered “normal weight” were now considered “overweight” or “obese,” with all the negative judgments, biases, and assumptions that go along with those labels. That is, the numbers and labels changed overnight—not the individuals’ bodies or their actual health. And here’s the most important part: those WHO metrics were largely based upon a report whose primary funders were two pharmaceutical companies selling weight loss drugs! Hmmm.
There’s even a substantial and growing body of research to show that BMI only weakly predicts longevity (and only at the statistical extremes). As outlined in this article, recapping a review looking at 350,000 people across 26 individual studies which found that the “overweight” BMI category was associated with greater longevity than the “normal” BMI range.
Another meta-analysis looking at nearly 3 million people around much of the world conducted by analysts at the Centers for Disease Control and Prevention found the highest risk of all-cause mortality in “underweight” individuals, while those labeled “overweight” by BMI actually had the lowest risk of all-cause mortality. The data showed no measurable difference between those given the “grade 1 obesity” versus “normal weight” labels.
There’s lots of other research showing similar data too. The bottom line: BMI is an unreliable indicator of health status for many reasons.
If you’d like to learn more about the history of BMI and some of that additional research, check out the book, Unapologetic Eating, by Alissa Rumsey. She does a great job outlining it.
In the meantime, remember that health is not a number.
Myth #5: White potatoes are bad for you or will make you gain weight.
Truth: White potatoes are a plant that’s full of fiber (which helps keep us feeling full) and other health-promoting nutrients. Compared to sweet potatoes, white potatoes have slightly more calories, slightly less sugar, and about an equivalent amount of fiber.
Sweet potatoes have a bit more vitamins A and C and contain some calcium, while white potatoes have more potassium, magnesium, and contain iron.
But guess what? We need ALL of these nutrients in our diet and fiber is exceptionally helpful for promoting health and protecting against various diseases. It’s helpful to eat a wide variety of nutrient-dense foods and other fun ones that nourish your soul; white, purple, or sweet potatoes included!
Remember, so many of the diet-driven, so-called “rules” about food and nutrition are blatantly false. Evidence-based nutrition is gentle and flexible!
Want to learn more about how to protect yourself from the allure and harm of diet culture? Read this blog: 3 Ways to Protect Yourself From Dieting and Diet Culture.