At Kion, we're huge believers in bio-individuality. We'll say it over, and over, and over again. There's no one-size-fits-all anything.
This is especially true when it comes to nutrition and diet.
Convenient as it might sound to find an optimal "human species diet," the fact is that we all have individual biological responses to food.
These responses are based on variables like genetics, lifestyle, gut microbiome, environment, gender, and activity levels. This is why that strict keto diet that worked so well for your neighbor caused you to gain weight, feel lethargic, and sleep like crap.
Instead of following general diet guidelines from an Instagram post or whatever diet book is currently trending on Amazon, recent science shows it's better to personalize your diet based on your unique body.
Yes, there are certainly some general principles everyone can benefit from when it comes to a healthy diet. Focusing on whole, unprocessed, organic, local, and seasonal foods will be beneficial for just about anyone.
But when it comes to deciding between keto or moderate carb, vegan or Paleo, OMAD or IF... How can one cut through the noise and figure out what will actually work for them?
This article will walk you through a number of ways to analyze your unique needs and create the perfect diet for you, so that you never have to follow another cookie-cutter meal plan again.
Why You Should Personalize Your Diet
Personalized nutrition, while still a new field, has become a topic of interest for researchers in the last decade.
Some of the most compelling research in support of a personalized dietary approach comes out of the Weizmann Institute of Science in Rehovot, Israel. From the study abstract:
“Here, we continuously monitored week-long glucose levels in an 800-person cohort, measured responses to 46,898 meals, and found high variability in the response to identical meals, suggesting that universal dietary recommendations may have limited utility.”
Their study confirmed a high variation in glucose responses to identical meals. Foods commonly considered as "blood sugar bombs" like cookies, bananas, sushi and whole-grain bread indeed produced sharp increases in blood sugar for some participants. But interestingly, other participants showed only a moderate response or none at all.
Ummm no blood sugar spike from cookies? We want those genetics!
Their findings indicate that reliance on something such as the glycemic index, which gives fixed numbers for each food item, may be relatively useless when compared to looking at individualized blood sugar response.
Applying this information with the right approach can be extremely valuable. After showing that each of us is unique in the way we absorb and metabolize nutrients, the scientists in Israel were able to use machine learning to develop an algorithm for accurately predicting personalized responses to meals. The algorithm integrates a number of factors like blood parameters, family history, physical activity, and gut microbiome to prescribe highly tailored dietary advice.
Another study, called the Food4Me Project, investigated 1,500 participants in seven European countries over a six month period. The participants were randomly given personalized dietary advice based on their genetic data, or instead told to follow standard dietary prescriptions such as eating lots of fruits and vegetables, lean meats and whole grains.
Those who were in the personalized diet cohort had much better health-related outcomes than those in the one-size-fits-all diet group.
The researchers of both studies concluded that personalized diets may be a better approach than generalized dietary recommendations for overall health.
How to Find Your Perfect Diet
It's clear that a personalize approach to nutrition is a superior option. But what factors do you actually need to consider when choosing the best food for you?
While there is no cut-and-dry answer just yet, here are a number of approaches you can take to craft your perfect diet.
Personalized Nutrition Approach No. 1: Genetic Testing
Before the creation of modern conveniences that allow us to eat tropical fruit in the North Pole, diet was almost strictly determined by the surrounding environment. Northern Europeans had vastly different diets than sub-Saharan Africans or Southeast Asians. As a result, over thousands of years, natives in peoples evolved genetic adaptations to the foods that were naturally available in their environment.
In other words, depending on where your ancestors are from, you're potentially predisposed to do better with certain foods.
For example, genetics affect the levels of carbohydrate-digesting salivary amylase, protein-digesting hydrochloric acid, and bile for metabolizing fats. This means that your capacity to extract energy from and properly digest certain foods is somewhat influenced by your genetics. If your ancestry lies in South America, where the traditional foods are usually high in carbohydrates and starches, chances are you'll have an easier time digesting and processing high-carbohydrate foods such as grains, tubers, and fruits.
If you know for certainty where most of your ancestors are from, this may be as far as you need to go. Simply eat as close as you can to the traditional diet in those regions, and you may find yourself faring much better than a Northern European eating steak tacos with extra guac every day.
However, most of us these days are--as fondly as we can phrase it--ancestral mutts. This a beautiful thing, but it also makes eating for your ancestry a bit trickier.
That's where genetic testing can come in handy.
Genetic testing allows you to see what genes you possess that may affect your responses to certain foods, preferred macronutrient ratios, susceptibility to nutrient deficiencies, and likelihood for certain lifestyle diseases.
Scientists have now pinpointed a number of genetic SNPs (single nucleotide polymorphisms) that can help you decide whether you should consume more or less folate, choline, vitamin C, fatty acids, starches, caffeine and more. The most commonly known genetic variants associated with diet include:
- MTHFR (folate, vitamin B metabolism)
- FTO (body weight and fat composition)
- TCF7L2 (blood sugar regulation)
- APOE ε4 (cholesterol)
- FADS1 (fatty acid metabolism)
- CYP1A2 (caffeine metabolism)
By doing a genetic test, you may be able to see what SNPs you possess, and adjust your diet accordingly.
A very large caveat here: Genetic testing is in its infancy. We don't actually know if the variants that show up on our genetic reports are actually activated. And even worse, some genetic tests are thought to be inaccurate or even useless. So take your genetic results with a grain of salt, and continue to do your research on the best platforms available.
Personalized Nutrition Approach No. 2: Test Your Blood Glucose Response to Foods
Standardized tools like the Glycemic Index or Glycemic Load attempt to determine how high a certain food generally will spike blood sugar. However, based on what we've learned from the Weizmann Institute, blood glucose responses are highly individual.
For instance, you may eat a banana and get a smooth dose of energy and a slight rise in blood glucose, whereas your spouse may get a huge blood sugar spike and an energy crash from that same amount of banana.
Testing your blood sugar response to certain food sounds tricky, but in actuality in only requires a glucometer and some test strips from your local pharmacy--a whopping $20 investment.
Instead of willy nilly taking your blood glucose after meals, it's best to take a scientific approach for the most accurate picture. Robb Wolf has a detailed description of how to do this, called the 7 Day Carb Test, in his book Wired to Eat.
For at least a week, note and observe your blood sugar response to everything you put in your body. You’ll want to start by measuring your blood glucose in the morning when your body is in a fasted state. According to the National Institute of Health, a fasting glucose level between 70 and 100 mg/dL (3.9 and 5.6 mmol/L) is considered normal. With that as a baseline, you’ll want to test immediately after each meal as well as two hours after each meal (less than 180 mg/dL is considered normal by the NIH two hours after a meal, however in the podcast with Robb Wolf a 90 to 115 mg/dL range is recommended).
You’re looking to find what spikes your blood sugar and what keeps it high for longer periods. With a week or so of this detailed logging, you'll be able to take a quick glance at something like a banana, a slice of pizza, or a handful of almonds and be able to gauge your response.
Personalized Nutrition Approach No. 3: Blood Testing
A good blood test can determine vitamin and mineral deficiencies that need to be filled from a supplement or food standpoint, such as low vitamin D status (vitamin D can be quite toxic if you’re simply taking it because you heard you should when in fact, your levels are actually already adequate), mineral status, thyroid status, cholesterol status, red blood cell and white blood cell levels, vitamin B, acidity, alkalinity and beyond. Some blood tests can even be used to determine food allergies and intolerances, although most of these are notoriously inaccurate, and will simply give you an exhausting “false positive” list of foods you shouldn’t eat.
Personalized Nutrition Approach No. 4: Stool Testing
A stool panel allows you to determine presence or absence of certain types of bacteria, yeast, fungus, parasites and digestive inflammation, all of which can then be used to determine the need for certain probiotics, cleansing compounds to eliminate things like small intestinal bacteria growth (SIBO) and Candida, the need or non-need to avoid fermentable substances such as simple sugars and starches, and more. Because poor digestion and malabsorption can lead to immune dysfunction, nutritional insufficiencies, and various disease states--along with food allergies and other toxicities--a stool panel provides you with a valuable idea of how your body is processing the foods you’re putting into it and potential things that need to be eliminated.
Personalized Nutrition Approach No. 5: Metabolic Rate Testing
A Resting Metabolic Rate test (RMR) determines the amount of energy (calories) your body is using at rest. This measurement is made by analyzing the amount of oxygen your body uses and the amount of carbon dioxide your body produces. Almost all of the energy your body produces is created through aerobic (oxygen utilizing) metabolism. The oxygen is then combined with carbohydrates and fats to make energy in your body’s tissues. When carbohydrates and fats are broken down to make energy carbon dioxide is produced. The percentage of the energy created from carbohydrates and fats--and how many calories you are burning at rest--can be determined by measuring the carbon dioxide your body produces. When paired with an exercise metabolic test, you can find out the same data relevant to exercise (e.g. how many calories you burn at any given heart rate). Armed with this information, you can then know precisely how many calories to eat.
Personalized Nutrition Approach No. 6: Listen To Your Body (Eat Intuitively)
This may not necessarily tell you what nutrients you’re lacking, but tracking what you eat and how it makes you feel will give you a sense of your ideal meals, if you’re eating enough, specific cravings you may have, food sensitivities, and a whole host of other personal data depending on how detailed you get. And you can get started right away, for free.
All you need to do is record what you eat and how it makes you feel. You can set specific times after eating to record and decide what to assess, such as energy level, mental clarity, etc.
If you want to more thoroughly assess specific food sensitivities or triggers, then you can begin by following a brief elimination diet. You remove all potential immune system inflammation triggers for a minimum of 30 days to give your body a chance to reduce any chronic inflammatory response to foods so that you get a good baseline for improvements. Then, when you reintroduce different foods, your body will have a much higher sensitivity. After the 30 days, you’ll methodically reintroduce specific foods and note whether you have a poor reaction to them.
There are several different elimination diet plans out there, but the most common foods that cause negative reactions and are eliminated are gluten, dairy, eggs, nuts, soy, corn, and alcohol.
When it comes to personalized nutrition, it’s important to recognize that there will also be certain nutrient, vitamin and mineral deficiencies that need to be addressed based on different factors such as age, religious or ethical preferences, or sporting demands.
- Aerobic and anaerobic athletes will have different needs, and while anaerobic athletes can restrict excess sugar and starches while still maintaining adequate glycogen levels for explosive or intense activities, aerobic sports will require a different approach.
- With vegan or vegetarian preferences, there are notorious deficits such as creatine, vitamin B12, DHA, taurine and amino acids.
- On the ends of the age spectrum, seniors and children will have far different needs to address. This also applies to gender differences- male and females will have unique aspects to address.
Outside of these general recommendations, you'll also be surprised at how much you can learn about yourself with a little bit of relatively simple testing and tracking. Once you’ve established and dialed in this understanding, unless you’re someone who likes to quantify and track every little detail, you can rely on your intuition with a much more sophisticated relationship to the food you put in your body.
On the other hand, if you're an over-achiever and want to tackle every tactic mentioned in this article, here's a general framework for testing and keeping your diet dialed in:
-Blood test once yearly
-Gut test once yearly
-7 day glucose tolerance test once yearly or as needed
-Metabolic test once in a lifetime or when your body composition or fitness dramatically changes
-DNA test once in a lifetime