By: Ashleigh G. Whittington | Apr 4, 2024

We live in a world that is inundated with nutrition and health content and, unfortunately, it’s not always accurate and can often cause a lot of fear and confusion. Specific foods, and sometimes whole categories of foods, are demonized and we are told that we should only be consuming certain things, and never consume others, and only consume others in “moderation” (which no one ever clearly defines for us), and sometimes consume others only in combination with or completely separate from others– the list goes on. I have taken the bait on many health claims over the years. Sometimes, after spending a lot of money on specific products and a lot of time worrying about doing everything “right”, I would learn they weren’t all they were purportedly cracked up to be and then have to abandon it. There’s a ton of excellent nutritional science information out there (see below), but some sources are either looking for clickbait, trying to sell you products or courses, or were also fooled by this junk science and think they’re helping people by spreading it. In this post, I explain a couple of the myths that have been thoroughly debunked by science, and share some tips for how to know which sources you can trust.

Myth #1: Carbs are Bad

First off, carbohydrates are one of the three macronutrients your body requires in order to survive, the other two being fat and protein. If you cut a large amount of carbohydrates out of your diet you are doing your body an incredible disservice and reducing its capacity to thrive not just at an optimal level but at a basic one. Your body uses carbohydrates for energy, especially during exercise. Carbs fuel your brain and central nervous system, help your body burn fat, and help preserve your muscle tissue by preventing your body from using protein as a primary energy source (Sims, 2016). Remember too that the supply of glycogen (carbohydrates stored in the muscles and liver) is limited so if you’re not refilling your tank the faster you burn through your stores. At a minimum, most people need anywhere from 130-160g of carbohydrates in order to support the central nervous system, maintain red blood cell production, keep the immune system running, and feed the brain, which requires ~60% of your body’s resting glucose utilization (Sims, 2016). If you want to do any kind of exercise, take a walk, or even just do your day to day tasks, you’ll need many more carbohydrates than that. 

The low-carb dieting craze has been around for a very long time (think Atkins, Paleo, Keto), and what is often prescribed in these diets is to significantly reduce carbohydrates and increase either fat or protein. There are a few problems with this, specifically as it relates to people who exercise:

1. Low-carbohydrate diets increase fatty acid oxidation, especially during exercise, which encourages fat storage. This happens because when the body recognizes there isn’t enough readily-available fuel (glucose) to support the stress it's under, it will go for the secondary source (stored fat). This isn’t a terrible thing in the short term, but if the body is continuously denied glucose, it will learn that this is a pattern it should remember and will continue to store fat for the next time it encounters that stress (Sims, 2016). This is one reason why most folks who go on these diets lose a lot of weight in the beginning and then plateau and/or regain the weight they lost. Then the people who promote these diets for weight loss tend to say you did it “wrong” and blame you for it “not working”, and then convince you to continue buying their books and supplements and subscriptions, and the cycle continues. (I apologize for the rant there, but I get very frustrated with these fad diets that take advantage of people!)

2. Eating a very low-carb, high fat diet also elevates cortisol (a steroid hormone that requires precise balance for healthy function), which increases catabolism (muscle breakdown) and harms protein synthesis: in other words, you're eating away at your muscles and are then unable to make more (Sims, 2016). This adds additional stress to the body which can harm the immune system.

3. The Ketogenic diet specifically has been a game changer in its ability to treat epilepsy, especially in children. There is also evidence that it may be helpful for lowering insulin levels in those with Type II diabetes. However, the keto diet causes excess sodium excretion in the urine, which results in lower blood volume and can manifest as headaches, orthostatic hypotension, fatigue, and compensatory tachycardia (fast heart rate). Long-term usage can cause fatty liver, hypoproteinemia (very low protein levels in the blood), and vitamin and mineral deficiencies. 

There are certain instances where carbohydrate intake needs to be monitored and adjusted, like for folks with diabetes, but it should NEVER be completely eliminated from the diet. I didn’t even touch on the importance of fiber, but you can read all about that in my post called Fabulous Fiber from January. No food or food group should be demonized and I hope the big takeaway here is that it's all about balance and understanding what your individual needs are. 

Myth #2: Seed Oils are Toxic

Seed oils have become a hotly debated topic in the wellness and nutrition space, mostly on  social media, but it has popped up in news outlets and other publications. Seed oils is an umbrella term for vegetable-based oils, including canola, soybean, corn, cottonseed, grapeseed, safflower, sunflower, rice bran, and peanut. Seed oils are rich in a fatty acid called linoleic acid, which gets converted into something called arachidonic acid, which is a key component in creating the fluidity required of cell membranes and therefore necessary for the function of all cells. Arachidonic acid also produces a range of eicosanoids (molecules that play a role in our innate immune response), some of which are considered proinflammatory and may increase levels of systemic inflammation. This is the claim that folks online are screaming from the rooftops. However, the amount of linoleic acid that is converted into arachidonic acid is actually quite limited because the process is highly inefficient, and arachidonic acid acts as both a pro- and anti-inflammatory mediator. 

There are two types of polyunsaturated fatty acids, Omega-6s and Omega-3s. You may have heard that Omega-6s are “bad” and Omega-3s are “good”. I have to tell you that it’s more complicated than that. These fats are considered essential, meaning we do not produce them on our own and instead have to ingest them through food. Linoleic acid falls in the Omega-6 camp and EPA, DHA, and ALA are all considered Omega-3s, which come from foods like fish, olive oil, and algae. The issue, in Western societies at least, is that our ratios for our fatty acid sources are skewed toward Omega-6s and saturated fats, with less attention paid to Omega-3s. This is due to many of the foods we get in restaurants or convenience stores utilizing the cheaper Omega-6 and saturated fats in production instead of the more expensive and less shelf-stable Omega-3s. The best way to ensure you’re getting enough fats within the proper ratios is to vary your sources. While paying attention to portion sizes, saute foods on the stove with some saturated fats like coconut and butter, use olive oil on your salads, and use canola or safflower oil for roasting foods in the oven. All of these fats have different flavors, consistencies, and nutritional properties, so demonizing a whole group of them seems detrimental to a balanced diet, in my opinion. If you have a heart condition or difficulty digesting and absorbing fat, you will need to make some considerations and discuss these with your doctor or nutritionist, but in general, the fear around seed oils is wildly overblown and they can be a supportive component to a healthy diet for most people.

Things to look out for

When encountering a social media post, advertisement, headline, article, or news story, stop for a moment and look for these 3 things to evaluate if it’s credible information from a credible source: 

1. Be skeptical, try not to take what you’re seeing directly at face value. It’s always ok to ask for evidence and develop a BS meter. Any credible science communicator interested in the truth will be open to criticism and learning new information. Some of these influencers or science communicators are too deep into their narrative to change their views and are concerned it will lose them followers and harm their credibility.

2. Look out for absolutist statements: “These are the 5 worst foods for your gut”, or “These are the most inflammatory foods”, etc. “Worst” and “best” are red flags because there is no situation where you can take 5 foods and they will be equally as beneficial or equally as harmful for two different individuals. Someone who has Crohn’s disease and someone who doesn’t will respond to eating an apple very differently. Anyone who uses this type of language is not interested in educating, they are interested in fear-mongering.

3. Do they allude to “studies show” or “science says” without evidence? If they do cite it, are they defensive when they interact with other people? Do they blame a single food or ingredient for the rise in incidence of any disease? If they understood how complicated these diseases are, they would know that one single thing wouldn’t be the driver and the other factors are ignored. Nutrition is multifactorial and oversimplification is dangerous. 

Here are some resources for wellness myth-busting and credible science communicators that I love:

Podcasts

Maintenance Phase

The Midlife Feast with Jenn Salib Huber

Burnt Toast

Unbiased Science

Rethinking Wellness

What the Actual Fork

Books

Food Politics: How the Food Industry Influences Nutrition and Health by Marion Nestle

Food Bullying: How to Avoid Buying BS by Michele Payn

What We Don’t Talk About When We Talk About Fat and “You Just Need to Lose Weight”: and 19 Other Myths About Fat People by Aubrey Gordon

The Wellness Trap by Christy Harrison

Fat Talk by Virginia Sole-Smith

 

Resources

1. Sims, S.T. Roar: How to Match Your Food and Fitness to Your Female Physiology for Optimum Performance, Great Health, and a Strong, Lean Body for Life. 2016. Rodale.