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  • Writer's picturePaige Smathers

8 Surprising Facts I Learned about Nutrition while Getting my PhD in Nutritional Sciences

They say the more you know, the more you realize you don’t know and that is 100% true in my experience as someone who has spent the better part of a decade knee-deep in the science of nutrition. My views about nutrition and the scientific world in general have changed pretty dramatically over that time. Because I know the topic of nutrition is fascinating to many people in the general public, I thought it might be fun for me to share some of the most surprising realizations I’ve come to in my years of studying nutrition.

1. Nutrition is an evolving science.

It’s important to get this one out there on the table first. Nutrition is such a young field when compared to other scientific fields. We only started truly researching nutrition over the past 100ish years which is nothing compared to fields like astronomy, biology, etc. And because of that, with nutrition (and really every scientific field) it’s very important to keep an open mind to the science changing as our technology improves and our understanding of phenomena become more clear. What we (culturally) are “sure” about today, may or may not hold up to the test of science and time. In other words, today’s “miracle diets” will more than likely be disavowed by future generations.

2. Carbs, proteins, and fats (all 3 are macronutrients) all play a role in health—the demonization of one is not supported by research.

Unless you have a specific medical condition or a genetic disease that prevents you from being able to freely consume all macronutrients, restricting specific food groups is not backed by research. Each macronutrient offers serves specific functions in your body and thus eliminating one can often result in health complications and frankly you’ll probably just feel like crap. Carbohydrates are the primary source of energy for our body’s cells and provide us with quick and readily available energy. Fats are important for cell function, hormones, temperature regulation, skin/hair health, and serve as critical energy storage. Finally, protein serves as the building blocks of the human body and is involved in immunity, muscle composition, hormones, and enzymes. The research always comes back to one theme—that restrictive dieting like this is ineffective, is largely unsustainable, puts you at higher risk for bingeing and doesn’t result in the promised improvements in body image.

3. Our intake cannot be pared down to a sole equation.

There are equations that attempt to calculate your energy requirements each day using your height, weight, age, sex, and activity levels as the influencing variables. Seems pretty detailed, right? The problem is that there are other parameters that can have large influences on our daily energy needs. This includes your past dieting history, muscle mass, hormones, genetics, and even more. Also, our energy expenditure varies from day to day. Most likely, you do not engage in the exact same activities each day and even small variations in your routine can change your energy requirements. However, what is really cool about our bodies is that we have internal cues and sensors to recognize and respond to energy needs. The problem is that we have learned to ignore these over the years with societally promoted behaviors like dieting and restriction. Getting back in tune to your hunger and fullness cues can help you harness the power of your body to recognize and honor your daily energy needs.

4. Human responses to nutrition are incredibly individualized.

Research does not cater to the individual. There are such large differences that exist between individuals that it becomes difficult—if not impossible—to apply “one size fits all” nutrition practices. Most randomized clinical trials (the gold standard of human research) are done on specific populations of people with specific conditions and often living in a similar region. We know that environmental factors and socioeconomic status can influence health outcomes, which limits the translatability of these specific studies. Furthermore, genetics can actually play a role in your response to nutrition. Some people are able to metabolize dietary fats better, some are better able to metabolize carbohydrates better. Some individuals are sensitive to changes in dietary cholesterol, others are not. Research studies most often do not account for genetic variability, as this is a relatively new technology. Therefore, you must take nutrition studies with a healthy dose of skepticism. Just because one study shows something, does not mean it will be that way for you. It also doesn’t mean that it is something safe for you to pursue on your own. Chasing after and implementing the newest research findings can be dangerous, expensive, mentally taxing, and never-ending.

5. The game of research telephone is a huge issue.

What you see in the media often has been diluted and misconstrued. The natural progression of research reaching the public is: 1) primary research article 2) university press release 3) local coverage outlets 4) national coverage outlets 5) self published bloggers and health gurus. At each step, it’s common for the take home messages to get misconstrued or taken grossly out of context. This is a huge issue preventing the public from receiving credible information and often this results in the spreading of potentially harmful information. I actually covered this in detail in another blog post if you’re interested in learning more.

6. Research is really slow and at times almost impossible in humans.

There are many factors that make human research so difficult. First, to do research in humans you have to first get what is known as IRB (institutional review board) approval by your university, which can be an incredible pain and feat to accomplish. You need to demonstrate that there is zero potential of harm to participants—this eliminates even the possibility of human research in numerous fields. Secondly, humans are messy and often unreliable, and this is especially true in measuring food consumption and dietary patterns in human subjects. In other words, people struggle to remember what they ate and even when they do, they can struggle to be honest because they’re often embarrassed about their eating. Not many people are willing to give up hours of their time to contribute to research, which sometimes will not provide incentives to participate. Even if you do get sufficient recruitment for a study, other issues to consider are participant dropout, inaccurate reporting, and failure to adhere to study parameters. For these reasons, human research can take years to fully and accurately complete, leaving big, unanswered and even unexplored questions looming for long periods of time.

7. MDs (Medical doctors) have an incredible wealth of knowledge, but should not be who you go to for nutrition advice.

I say this a lot: credentials are not everything but you wouldn’t go to your plumber for accounting advice so why would you go to your doctor for nutrition advice? Medical doctors are trained in so many different areas, but unfortunately only get a few lectures on nutrition over their entire education. Therefore, sometimes the nutrition information conveyed by medical doctors can be flawed and inaccurate. Dietitians, on the other hand, receive 4+ years of specific nutrition education on top of a dietetic internship in which they train with experienced dietitians to gain further experience. Medical professionals all went to school to achieve very tailored and specific educations. We are designed to work as a team and to complement each other, so advocate for proper medical care when necessary.

8. Nutrition at the individual level should actually be very simple.

Research gets nitty gritty to try and better understand the way our bodies respond to changes. But time and time again, research shows that overcomplicating things doesn’t work out in the long-term. Really detailed research on specific macro/micronutrients and compounds does serve a purpose and is important for understanding specific metabolic processes, but this doesn’t mean it translates well to applicability at the individual level. When we overcomplicate things and get overly rigid and mathematical in our nutritional practices, we often neglect to look at the big picture and even see health parameters suffer as a result. Nutrition is just one contributing factor to overall health. Getting hyper-focused on one aspect of nutrition and eating will cause you to neglect others which is going to be more detrimental to your health than applying an overall balanced approach to food and your body. Eat food that sounds good, feels good in your body, and makes you happy. I’m confident you’ll find that with this approach you’ll find your overall health (mental, physical, emotional) improve.

Hopefully this gave you a little peek into the way my mind has changed over the past years of studying nutrition in detail. The take home messages are: don’t overcomplicate nutrition, make sure you’re getting your nutritional advice from registered dietitians who are trained to provide this, and finally, be skeptical of things you read in the media and always question trending nutritional stories.

Of course, I expect to continue to have realizations and to change my mind in the future. This is only a brief introduction into what I’ve learned and I look forward to lots of more learning and evolving with time: both in the science of nutrition and in my own practices and beliefs about nutrition as well.

Interested in learning more about the science of nutrition, body image, intuitive eating and more? Sign up for our upcoming workshop in Salt Lake City, UT on April 4 at the University of Utah campus for a night of learning, community and fun!


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