Chances are, you’ve noticed the nutrition facts label on a food product. If not, go grab something and follow along.
You’ll notice the calories, the carbs, the fats, and the micronutrients like iron, sodium, potassium, or calcium. You’ll also notice that each of these numbers have a percentage next to them. What do these mean? Well, it’s referring to the percent of your daily needs provided by the product.
We all need a certain amount of calories, vitamins, and minerals for our bodies to function properly. In fact, many vitamins and minerals are “essential” meaning that our bodies cannot produce them ourselves but we still need to consume them to survive.
They are so important, that governmental agencies have entire departments dedicated to the nutritional health and wellbeing of its citizens. They provide large, population-wide recommendations that work to keep the country healthy and free of deficiencies.
The International Society of Nutrigenetics and Nutrigenomics would describe this type of population-wide public health recommendation as the outer ring of nutrition.1 It creates recommendations to suit the general public and encompass the most amount of people possible.
However, what individuals need to thrive and stay healthy varies greatly by a number of factors. While these recommendations may keep the public healthy, the focus is greatly shifting inward from this ring to what we need to do to keep the individual healthy and happy.
The Center Ring
The next inner ring to consider is our nutrition recommendations related to our phenotype.
Our phenotype is the set of characteristics that has to do with our body’s physical structure. This includes features like:
- physical activity level and
- biochemical markers such as blood levels of certain nutrients.
All of these factors affect how many calories we need to maintain a healthy weight and what types of foods we need to consume the right amount of nutrients for our body.
This ring is important because large, population-wide recommendations cannot predict that you may have a B vitamin deficiency or that your activity level requires more calories than a typical 25-year-old woman.
Only by examining your lifestyle choices and looking at biochemical tests can we do this. For this reason, we have resources and professionals who exist to help us enhance our nutrition and our health.
A registered dietitian is a credentialed health professional who specializes in just this. They work one on one with the individual to calculate exactly the calories you need for your goals, they analyze blood samples to see if you are deficient in any nutrients, and they learn about your eating habits, your preferences, your restrictions, and your cultural practices surrounding food. They’re the “OG” in personalized nutrition, as they’re trained to optimize nutrition for individuals.
However, in this era of a $4.2 trillion wellness industry, it’s no surprise that meeting weekly in person with a dietitian to institute personalized nutrition advice is being overlooked.2
Rather than going to an office, talking for an hour and then going to a lab for a blood test, you can collect your own blood at home and mail it in for analysis. Even further, based on these results, companies are now offering the exact supplements people need, delivered to their door, prepared in precisely the right quantities.
While this area of personalized nutrition continues to grow, for a long time, this is about as personal as nutrition could get. Determining how much of what nutrient we needed. While this is a part of personalized nutrition, advances in science have allowed us to get even more personal.
The Inner Ring
We may know how many calories or the exact nutrients we need, but does it matter from what types of food we get them from? Likely, yes. This inner ring of personalized nutrition refers to how our genes and our microbiome contribute to our nutritional needs.
When talking about our genes and nutrition, we are referring to the area of nutrigenetics. This term refers to the idea that, based on our genes, we can change our diet to decrease the risk of disease. The human genome project allowed us to see our entire genetic makeup.
Within this, we can also see which genetic variations make some people more likely to be obese or more susceptible to chronic disease. With this information, we can create personalized nutrition plans to decrease these risks.
For example, a genetic variation may make someone more susceptible to developing cardiovascular disease (CVD) in their lifetime. We know that CVD risk is also very tied to diet. For such an individual, we can counsel them to follow a diet low in saturated fat and salt and create a lifestyle that will lessen their risk for developing the disease.
The microbiome is another aspect to this inner ring of personalized nutrition. This is the trillions of healthy bacteria that live in our intestines. Studies are beginning to show that the microbiome plays an enormous role in multiple aspects of our health that range far past just digestion and our immune system.
Studies are underway regarding how our microbiome can predict our glycemic response – or the way our body reacts to carbohydrates in foods.
One study followed 800 individuals consuming the same diet and saw drastic changes in their glycemic response. From this, they were able to create an algorithm considering an individual’s phenotype and microbiome to better predict glycemic response to meals.
They found that those following the diet more specific to their microbiome and tailored to their glycemic response in foods had lower and steadier blood glucose levels throughout the duration of the study.3
What does this all mean?
It's important to remember that neither genes nor the microbiome tells the whole story of our nutritional needs. While these areas are important and will continue to grow and influence our eating habits, we cannot ignore these other rings of nutrition.
Phenotype is still a very relevant factor to consider when providing nutritional recommendations. In addition, metabolism and disease risk is not only associated with diet. We should also consider other aspects of health such as physical activity levels, sleep habits, stress, and overall mental health.
Another significant area for consideration is food preferences and culture. Can we personalize these recommendations to meet the needs of people with dietary restrictions due to religious reasons or to follow a traditional diet?
Also, how can we match them to a person’s personal preferences? Will we still enjoy a bowl of ice-cream the same way if we know that “my glycemic response to this bowl of ice-cream is far worse than the average person?”
These are the types of questions we should be addressing as this movement towards personalized nutrition moves forward.
It is also important to remember that most of these personalized nutrition prescriptions are just individualized diets. If we know one thing about diets, it’s that many people have trouble with compliance. Is having a diet that is specific to one person enough to change their likelihood of following it?
Finally, from an economic and ethical standpoint, where does personalized nutrition stand?
As of now, having your genes or microbiome tested costs money and many companies are catching on quick to the opportunity. How will paying for this information affect inequality in health care, how is the data managed, and how do we best address disease susceptibility and dietary changes in those from varying economic and cultural backgrounds?
While we may not know the answers to all of these questions or exactly what people need to eat at every moment of the day, science has come a long way. Our genes and our microbiome seem to play a much larger role than ever understood and may help drastically with disease prevention and management.
The future of personalized nutrition is bright, but it still has challenging obstacles to overcome.
 Ferguson LR, De Caterina R, Görman U, et al. Guide and Position of the International Society of Nutrigenetics/Nutrigenomics on Personalised Nutrition: Part 1 - Fields of Precision Nutrition. In:Journal of Nutrigenetics and Nutrigenomics. Vol 9. S. Karger AG; 2016:12-27. doi:10.1159/000445350
 Beth McGroarty. Wellness Industry Statistics and Facts. https://globalwellnessinstitute.org/press-room/statistics-and-facts/. Accessed August 21, 2019.
 Zeevi D, Korem T, Zmora N, et al. Personalized Nutrition by Prediction of Glycemic Responses Article Personalized Nutrition by Prediction of Glycemic Responses. Cell. 2015;163:1079-1094. doi:10.1016/j.cell.2015.11.001