Low-carb or low-fat? No fruits or no meat? Only meat or only fruits? Are you genetically predisposed towards obesity or miraculously endowed with a clockwork metabolism? Paradoxically, there are so many recommended nutritional guidelines, with most of them contradicting one another, that it is now impossible to look at the nutritional studies performed and obtain valuable data for personal use.
Given the level of advancement that medical technology enjoys in 2018, this situation is thoroughly unacceptable. Even the American Heart Association (AHA), the National Cholesterol Education Program (NCEP), and the American Diabetes Association (ADA) can’t seem to agree on it.1 Are we supposed to look at dietary reference intakes (DRIs), estimated average requirements (EARs), or recommended dietary allowances (RDAs)?
The Trouble with Observational Studies
The balanced, reasonable answer is to be simultaneously looking at all and at neither of them, in the sense that you should try to critically engage with the data and the results of as many of these official standards, but not trust any of them blindly. The main reason for this is that the majority of nutritional guidelines come from observational studies, rather than interventional ones, where establishing and mapping a cause-effect relationship is the primary goal. The latter usually involves keeping people in labs (hence the term “feeding studies”), so that the only sources of nutrition are given by the researchers themselves. This is not only unfeasible on a large scale, but it is also impossible for a long period of time, both of which are essential elements in order to ascertain the proper impact of certain food items or behaviors.
In the scientific world, observational studies are the most cost-effective way to obtain a big enough sample size in order to issue statements for a general population. Their conclusions are always labeled as associations, rather than being framed as rapports of cause and effect, mainly because they admit that not all dietary variables have been under close scrutiny. However, media outlets rarely frame these findings according to the scientific wording of the study. You’ll mostly read or hear “Bacon Is Good/Terrible for You”, “Alcohol Helps/Prevents Weight Loss,” “Kale Is SuperBad for Your Health”, or “6x Chocolate Bars a Week for a Stronger Heart”—you get the idea.
Commonly, observational studies rely on memory-based dietary assessment methods, meaning that they will often ask participants to recall what they ate, when, and in what amount. Needless to say, this approach is fundamentally flawed, given that so many individuals consciously (or unconsciously) deliver biased and inaccurate information. I mean, I love my peanut butter thickly laid out on as tiny a slice of bread as possible—it still counts as one slice, right?
Unsurprisingly, as much as 63% of the data that the National Health and Nutrition Examination Survey (NHANES) relied on for its four-decade study on nutrition was found to be “not physiologically plausible” precisely because of this memory factor.2 Needless to say that my love for peanut butter, guacamole, and white wine should not be a decisive part of any scientific data with a claim to objectivity.3 It doesn’t help if there are another two million opinions spanning over 40 years. Each and every one of us has their mouthwatering, tantalizing treat that we just can’t seem to help ourselves from having a bit more than we ought to.
Study Yourself: Be Your Own Scientist
As it turns out, many of these contradictory health claims can be simultaneously valid, just not that one about the chocolate bars. Odds are you are eating too much chocolate, like me, and guac toast. My precious. The general nutritional paradox we currently find ourselves in is caused by the variety in the target population of each study.4
Some were done on people with specific issues, such as an elderly population with elevated blood cholesterol, adults with moderate physical activity, or obese teens, while others welcome a great diversity of patients. From these claims, a number of diets with cult-like followers have emerged, but their claims to be the best way of eating are just as tenuous as the nutritional studies that support them. I too was a low-carb evangelist until I gradually included whole foods in my diet. For me, this translated in a visible boost to my energy levels. For instance, I could do anywhere from 10 to 20% more sets and reps with the same weights.
The only way to reconcile all of this information about nutrition is to run your own diet experiments. A comprehensive study of 800 people eating almost 47,000 meals that were published in the Cell journal just several years back indicated that “universal dietary recommendations have limited utility.”5 Given that each and every one of our bodies responds to the same meal differently, it becomes next to impossible to figure out more general guidelines for one’s nutrition. However, by using a thorough approach, you can discover the effect that certain food items and food behaviors have upon your own constitution.
First of all, it is important for you to get some measurements before you begin your experiment. These will constitute your starting point, and the more measurements you make, the more will be revealed about how your body reacted to the experiment you’ve performed. My analysis, although reductive in some aspects, gives you the building blocks to generate your own investigation of your corporeal self. In order to validate your findings, consulting a couple of physicians and a nutritionist will give you the much-needed second opinion on what has changed in your body and what it means.
It is important for you to get accustomed with these aspects of human physiology, in case you haven’t already, as they will facilitate a more insightful understanding of your health and potential in the long run. Testing will cost a little, but the results are literally invaluable since they will reveal personalized data about your own body that you can use in order to formulate both health and nutritional hypotheses, assuming that you’re past your growth phase (around 18 to 22 years, on average).
Personally, I see my metabolism, cardiovascular health and body composition as the baseline indicators of my current health. These are also the bare minimum elements you should follow as part of your diet experiment. For the first two, gathering information could not be easier, since they come via blood tests. The best part about this testing is that your insurance will cover most (if not all, in some cases) of the costs, so you can talk to your general practitioner (or family doctor for some) in order to see what you can benefit from. They will be happy to see you take an active interest in your health and the way in which food items and behaviors impact your body.
The Puzzle That Is Your Body
Metabolism is commonly tested for by means of blood ketones, blood glucose, and the glucose-ketone index. For a comprehensive investigation, metabolic testing, specifically your resting metabolic rate (RMR), will speak volumes about your body. If you can afford a full analysis of your aerobic threshold, VO2 max, and DHEA hormone during a stress and resilience challenge, testing methods which are currently implemented outside laboratories in several fitness franchises around the world, do not hesitate to do it.
There is just no replacement for an accurate read of how your body consumes calories both in a resting state, as well as during physical activity. It may cost you a bit, but it will give you a glimpse within yourself and your health, which is invaluable for anyone looking to improve their fitness, performance, or general aspect. Alternatively, certain hand-held devices might provide you with some interesting readings, but you should always take these results with a pinch of salt as they are not very accurate.
For a comprehensive study of your cardiovascular system, your blood panel needs to include total cholesterol, low-density lipoprotein (known in folklore as the “evil” fat, LDL), high-density lipoprotein (HDL, the superhero fat), and triglycerides. Last, but not least, another common test you can bleed a few drops for is the C-reactive protein (CRP), which is a marker for inflammation commonly used to assess cardiovascular risks.6 It’s nice to check on your ticker once in a while. After all, it does keep you alive.
Lastly, body composition is also important for a diet endeavor. Any changes in your eating patterns will most likely reflect in your weight. But if you don’t track your composition, particularly your muscle mass, percentage of fat, and water, you won’t know how things changed. The “calculator” version of the body mass index (BMI), the one that uses your height and weight to give you a number, is renowned for not being able to distinguish between a couch potato and an athletic runner of the same height and weight. The good part is that if you perform a comprehensive metabolic assessment, you’ll likely get your BMI, too.
How to Conduct Your Experiment
The experimentation cycle will help you with the investigation per se. You will need a hypothesis (i.e. does a low-fat diet help me more than my current low-carb one) which is then followed by extant literature on the topic. Always go to the studies referenced by media, check their approach, their target population, who funded it, and the overall thoroughness. Are they just observational? How reliable is their data? Then compile your findings.
Next up is to settle on your case design. Ideally, you would change just one factor. For instance, I performed a similar investigation when I gave up processed sugar and it did wonders to my fat percentage and mood. Another example is when a close friend of mine tried intermittent fasting and achieved his fantasy washboard abs. You can also adopt a more complex behavior, such as a vegetarian/vegan diet, but the more variables you work with, the less likely it becomes for you to distinguish a cause and effect relationship between certain food items and behaviors. You want to maintain the said behavior/change for at least 30 days (ideally 45) before moving on to the next stage.
Throughout this timeframe, you need to keep track of what is going on. Use a research diary where you can jot down your initial measurements and your weight as you go through your trial (measure no more than twice a week). Note the areas around your body where you’d like to see changes, such as waist or hips (same frequency). Write down these measurements, along with what you eat, as precisely as you can. You can keep everything in a folder, on your laptop, or even make a neat table with your numbers for easier percentages, ratios, and bottom lines.
Most importantly, always take a photo of your meals. Since they have a time and date, these will be your hard evidence when trying to make odds and ends of your calorie measurements. Calorie-counting is just unfeasible, so this will help you better gauge appropriate food quantities. Your body weight will fluctuate over the timeframe of your experiment, which is why these numbers are helpful at the end.
At the end of your diet experiment case study, the data you have gathered will hopefully either validate or invalidate your hypothesis. Sometimes the improvements are visible without any additional testing, such as in the case of improved performance, visible weight loss, or muscle gain. However, to make sure that you’re not hurting yourself in the long-run with the behavior you’ve chosen to adopt, the safest route would be to repeat the same battery of tests you started with. This will quantify just how much has changed and help you better understand the progress you’ve made. It will also provide an appropriate conclusion to your scientific investigation and help you better understand your own body.
Take Control of Your Nutrition
It has become imperative for each of us to experiment with the diets or nutritional principles we choose to abide by. There are just so many diverging opinions and personalized responses to what is currently out there that the only way to be sure is to take matters into your own hands. By using the methodological structure presented by this article, you can test for yourself what seems right and gather every bit of information on how you react to it before deciding on whether to become an evangelist of something that may not be worth preaching.
Whether you are a scientist already or not, today’s access to information combined with readily available and affordable medical testing makes it possible for anyone to become as thorough as a researcher would be when trying to determine what is the most reasonable nutritional advice for your own body. Just remember that certain changes often take serious amounts of time and adherence to the behavior(s) to accurately reflect on your physical, emotional, and mental states.
We already know that certain fat deposits can take months, or even years, to break down, depending on your body, nutrition, and level of activity. Some of the chemicals released into your bloodstream by the weight loss process might initially make you feel bad before making you feel overall amazing.7 Especially in these cases, knowing what has triggered your condition and/or feelings is vital.
Ultimately, after several of these diet experiments, you will not only become your own nutritional expert, but you will also know your body well enough to understand what eating certain new foods will do to you based on their macronutrients. For example, if you are aware of the fact that sugary drinks will mess up your insulin resistance and, therefore, weight loss efficiency, then you’ll be less tempted to crave them.
1. American Diabetes Association, “So Many Nutrition Recommendations—Contradictory or Compatible?”, Diabetes.org, January 2003, accessed March 31, 2018.
2. Edward Archer, Gregory Pavela, and Carl Lavie, “The Inadmissibility of What We Eat in America and NHANES Dietary Data in Nutrition and Obesity Research and the Scientific Formulation of National Dietary Guidelines“, mayoclinicproceedings.org, July 2015, accessed March 31, 2018.
3. Julia Belluz, “I asked 8 researchers why the science of nutrition is so messy. Here’s what they said”, August 2016, accessed March 31, 2018.
4. Christopher Gardner and Michael Stanton, “Digesting Dietary Data: Why are there so many contradictory nutrition studies, and how can they be improved?”, June 2014, accessed March 31, 2018.
5. Zeevi et al, “Personalized Nutrition by Prediction of Glycemic Responses”, November 2015, accessed March 31, 2018.
6. Jesse Adams and Fred Apple, “New Blood Tests for Detecting Heart Disease”, January 2004, accessed March 31, 2018.
7. Michele Le Merrill et al, “Toxicological Function of Adipose Tissue: Focus on Persistent Organic Pollutants”, February 2013, accessed March 31, 2018.