If you’ve ever felt overwhelmed by ever-evolving nutrition science, you are not alone. Following every emerging piece of research keeps you in constant contradiction. First it’s low-carb, then it’s low-fat, next carnivore, then vegan. It’s important to acknowledge that nutrition scientists often summarize their study results in simplified and sensationalized ways in order to get media attention which increases their likelihood of receiving funding for future research. They are flawed humans who live in the same fatphobic culture we all do and as such, we should evaluate what we accept as fact through a critical lens. Here are 9 of the top nutrition myths you don’t have to worry about anymore!
A 2017 meta-analysis and systematic review that compared weight loss between low-carb and low-fat diets found zero meaningful benefit in body fat loss or daily energy expenditure. In fact, one study found that those who followed low-fat diets lost slightly more weight.
Japan is one of the top consumers of carbs, eating white rice with almost every meal and they still have the lowest ‘obesity’* rate. Meanwhile, US carbohydrate intake has fallen over the years while average body size continues to increase. Weight gain is clearly more complex than carbohydrates alone.
This narrative became popularized thanks to the 2014 documentary Fed Up which showed two MRI brain scans side-by-side with the labels ‘SUGAR’ and ‘COCAINE’ underneath each. What it fails to mention is that the same areas of the brain light up when you play with puppies, listen to music, and receive hugs.
Later in 2017, a research review done on rats perpetuated this myth. Again, they leave out important details like:
Sugar is not the problem. The problem is restriction, especially among those who struggle with binge-eating disorder. The cultural demonisation of sugar is what makes it especially enticing. If it were true that sugar were addictive, dependency and physical withdrawal symptoms would be present, and we know that they aren’t.
How many times have you heard this one? It’s no secret that eating 7.5 candy bars a day isn’t going to support your health goals, but let’s take a step back from black-and-white thinking to gain a sensible perspective. A toxin is a substance that is poisonous because the body isn’t capable of processing it. Not only can sugar be processed, but the brain uses 20% of the body’s daily total supply as its preferred source of energy!
When we consider the nutrition research that supports the ‘sugar is toxic’ narrative, it’s important to acknowledge that much of it comes from self-reported data. High-quality studies on eating done in a controlled lab are expensive, time-consuming, and therefore non-existent. As such, reported results are inaccurate and likely fraught with disordered eating.
This is where it gets interesting. Studies have shown that people who experience weight stigma tend to consume higher quantities of sugary foods. But before we assume that sugar is causing adverse effects like increased risk of cardiovascular problems, remember that correlation does not equal causation. Additional contributors to cardiovascular problems include the stress associated with being discriminated against for body weight, repeated weight loss and regain (chronic dieting), and having a disordered relationship with food. It’s like blaming yellow teeth for lung cancer without looking at cigarette smoking as a contributor to the equation.
Researchers used to hypothesize that too much dietary cholesterol would result in higher levels of cholesterol in the blood. What we know now is that when dietary cholesterol levels rise, our liver makes less while increasing the amount made as bile (which gets excreted). About two-thirds of the population experiences no impact from dietary cholesterol on overall cholesterol in the blood, thanks to these well-functioning mechanisms. The other third of the population experiences a slight rise in overall cholesterol levels, however, this doesn’t affect cardiovascular risk. Cardiovascular risk is in fact a result of combined high dietary cholesterol and high levels of saturated fat. Cholesterol itself isn’t something to worry about.
This is yet another reductionist argument considering a whole host of things (diet, stress, exercise, sleep, etc.) contribute to inflammation (which is not always necessarily a bad thing). The myth that dairy is pro-inflammatory comes from the saturated fat content, however studies that associate saturated fat with inflammation don’t differentiate where that saturated fat comes from. With the exception of butter, which has an altered nutrient structure, dairy from milk, cream, cheese, and yogurt show no negative impact on cardiovascular risk and LDL. In fact, they’re potentially even beneficial. Experts theorize that the combined effects of the structure of dairy nutrients keep the saturated fat from being digested and absorbed by our gut. What’s more, a 2017 systematic review determined dairy even seems to have a weak anti-inflammatory effect on the body.
About 4% of the population legitimately has to avoid gluten based on having celiac disease, but it’s become increasing popular to test for gluten intolerance as management for autoimmune diseases among other conditions. There is no biological marker that identifies non-celiac gluten sensitivity (NCGS). That means the only way to diagnose NCGS is based on self-reported symptoms. In 2013, a randomized control trial concluded that the ‘nocebo effect’ has a strong influence on people’s symptoms. Meaning that if people think gluten will make them sick, they’ll actually feel bad after eating it.
Fat is an essential part of our diet that helps us absorb micronutrients like vitamins A, D, E and K, form parts of our cells, make hormones, and have energy. Foods have different ratios of saturated and unsaturated triglycerides – the small compounds our gut breaks down food into. You can easily tell if a fat is saturated, like butter and coconut oil, because it’s solid at room temperature, as opposed to olive oil which is liquid and mostly unsaturated. Fat gets transported to be used or stored after it’s absorbed in the gut. As you know, fat and water don’t mix, so triglycerides and cholesterol become one of 4 types of lipoproteins – chylomicrons, very low-density lipoproteins (VLDL), low-density lipoproteins (LDL), or high-density lipoproteins (HDL). The best way to reduce the risk of cardiovascular disease is to lower LDL levels by avoiding trans fats, reducing saturated fat, increasing fiber, exercising, quitting smoking, and reducing alcohol consumption.
Everything we eat is processed to a degree. According to the Department of Agriculture, processed food are any raw agricultural commodities that have been washed, cleaned, milled, cut, chopped, heated, pasteurized, blanched, cooked, canned, frozen, dried, dehydrated, mixed or packaged — anything done to them that alters their natural state.This classic myth is promoted by wellness culture that idolizes ‘natural’ as being morally good. Fearmongering about GMOs, sweeteners, vegetable oils, and dyes and flavors is spread by social media testimonials and anecdotes without a basis in sound scientific evidence. What we do know is that no good scientific evidence exists that eating processed food causes significant weight gain or poor health outcomes.
Bodies don’t operate requiring energy only at certain times of the day. Nutrition recommendations are meant to be considered on an average over time, not meal to meal. Our bodies adapt by absorbing or excreting nutrient imbalances. Denying your body energy after a long day at work will only set you up for eating past comfort once you’re ‘allowed’ to eat again.
In the end, we eat food, not nutrients. With that perspective, we rob ourselves of the pleasure, connection, community, and celebration that food also provides. Having a healthy relationship with food means accepting that it can serve more purposes than just nutrients alone. On top of that, weight loss and gain are incredibly nuanced, and attributing either one to singular foods or macronutrients is a very reductionist way of approaching health. If you’re looking for support in developing a healthier relationship with food, I’d invite you to schedule a free discovery call for 1:1 nutrition counseling. The goal of our work together is to tune into (and eventually trust!) your body signals to meet your physical and psychological needs and learn to let go and challenge the rules, beliefs, and thoughts you have around food.