Nutrigenetics vs Nutrigenomics & What They Mean to Clients

As biological and genetic technology has improved, it has also gotten less expensive. Direct-to-consumer genetic testing is now accessible to most people. Your clients are going to be increasingly curious about these tests and how they could help them. It's up to trainers and coaches to stay informed.

Among the many genetic products consumers can now get at a reasonable price are health and fitness DNA tests. These are also known as lifestyle tests. Unlike medical-based genetic testing, they are not designed to show you anything about disease risk, such as with Alzheimer's disease or even chronic diseases. Instead, they provide information about nutrition, weight loss and maintenance, body composition, and fitness.

The lifestyle genetic tests your clients take are based on nutrigenetics and nutrigenomics. These two very similar words represent different areas of study and information. Before you begin trying to explain genetic testing to clients and how you can use them to guide health goals and strategies, make sure you understand these and other terms.

The Intersection of Genetics, the Genome, and Nutrition

The practice of good nutrition can be general. For instance, eating more vegetables and less refined sugar is a broad rule of good nutrition that anyone can follow. Decreasing calorie intake and increasing physical activity is a general guideline for anyone to lose weight. Learn more about the general guidelines and important benefits of an overall healthy diet.

However, despite these generalities, nutrition and health are also highly individualized. Long before genetic testing, it was obvious that not everyone responds the same way to the same diet or nutrition strategy. For instance, some people find it easier to maintain a healthy body composition, while others, even following a good diet and exercise routine, will struggle.

What genetic testing can do is provide more details about an individual's genome, their specific DNA and genes, with respect to food and nutrition. It can tell you, for example, if eating a higher percentage of protein daily will help you lose weight, or if it makes no difference how you divide your macros.

The science of genetics and how it relates to nutrition is evolving. As a professional in the health and fitness industry, it's important to understand terms like nutrigenetics and nutrigenomics, to know what these tests can do for clients, what their limitations are, and any risks.

What is Nutrigenetics?

Nutrigenetics is the study of how genes determine the effects nutrients have on the body and health. How your body responds to what you eat is your unique nutrigenetic profile. This is based on your specific genes that relate to things like nutrient absorption and utilization, food intolerances, allergies, and nutrient deficiencies.

For instance, nutrigenetic information can outline if you have the genetic variation that makes you prone to poor vitamin B12 absorption, which can lead to deficiency and a condition called pernicious anemia. Nutrigenetic information also provides details about how your body composition and weight respond to certain proportions of macronutrients and how your health measures like blood sugar and cholesterol change based on what you eat.

What is Nutritional Genomics, or Nutrigenomics?

Think of nutrigenomics as the opposite of nutrigenetics. While nutrigenetics provides information about how your specific genome should inform what and how to eat to maximize health, nutrigenomics is all about how the foods you choose change how your genes are expressed. These changes can have a big impact on health, wellness, weight, and fitness.

An example of a nutrigenomic study shows how food and nutrients can have a major impact on health markers through DNA. The study looked at the health of adults whose mothers lived through a famine when they were pregnant. These women consumed as little as 400 to 800 calories per day during the famine period.

Decades later researchers studied health markers in the adult children of these mothers. They had elevated rates of obesity, cardiovascular disease, and poor health markers, like high cholesterol. Researchers have found that nutrients consumed can impact how gene expression vaires in individuals and even in developing fetuses (1). The effects of nutrition are important for an individual, but also for generations to come.

What is the Difference Between Nutrigenetics and Nutrigenomics for Clients?

Do your clients really need to understand these differences between nutrigenetics and nutrigenomics? Probably not. Lifestyle DNA tests will use all kinds of information from these areas of study, and some even use the terms interchangeably. It can be confusing for clients.

What they really want to know is that the test they are getting will be beneficial. That it will tell them more about how they process foods, how what they eat impacts their weight and health, and other useful pieces of individualized information.

Technically speaking, nutrigenomics is more useful for addressing medical and health issues, such as disease prevention. This can be a little outside the scope of practice for a trainer or nutrition coach. It's better to focus on the information from nutrigenetics to optimize health in general and meet weight, fitness, and body composition goals.

Benefits of Using Lifestyle Genetics Tests

So, should your clients be using lifestyle genetics tests? There are a lot of good reasons to give it a try. Make sure you understand all the benefits and the risks before helping your clients process their information.

Personalized Nutrition

Current DNA tests for nutrition and health aren't perfect. But what they can do is help you guide clients to create more personalized diet plans. Experts agree that there is no such thing as a universal "best" diet (2). Individual genomes, environment, lifestyle, and so many factors align to determine what a "best" diet is for each person. A lifestyle DNA test is a good place to start.

Meeting Goals

Clients work with you because they want to change something about their weight, health, or fitness. They have goals to meet, and DNA testing is another tool in your toolbox to help them do that.

For instance, a good test will outline a client's weight loss genotype. Genetic profile scores include ‘normal,' ‘below average,' and ‘low,' and can help explain to clients why they may struggle to lose or maintain weight. These results can also help you craft better plans for them that will lead to greater success.

Improved Motivation

When clients get more information about their personal genome, it can be motivating. For many, the process of trying to change weight or fitness is frustrating because it's confusing. Your clients may follow general guidelines with poor results and want to quit. With personalized information, they have a clearer understanding of how and why they respond to different diets and fitness plans, which is inspiring and motivating.

Better Overall Health

While your role as a trainer or nutrition coach is limited in terms of medicine, providing clients with a more tailored diet and fitness routine will naturally result in better health outcomes. DNA testing can provide information about how an individual's health markers respond to what they eat.

For instance, a typical lifestyle test can tell you about how insulin sensitivity responds to fat intake. A client with a ‘highly sensitive' score may actually benefit from eating a higher percentage of fat daily. Minimizing fat is often considered to be a healthy dietary choice, but for some people, it makes sense to eat more. Only a DNA test can provide this information.

Risks of Genetic Testing

Genetic tests may be an important part of the future of fitness, health, and training, but it isn't always great. While the benefits of these tests are significant, there are also some downsides. Make sure you understand the risks and know how to use test results with clients to minimize them.

Unrealistic Expectations

Prepare your clients ahead of a genetic test. They may have expectations that simply aren't realistic, which can lead to disappointment. Make sure they understand exactly what these tests can tell them and what the limitations are.

Poor or Inaccurate Tests

Help your clients find a reputable testing company. As the industry grows there are bound to be companies offering bad tests that are inaccurate, that don't provide any conclusive results, or that come with poor interpretations of the results. There may even be sham companies looking to defraud consumers to make money. Look for certain factors when choosing a testing company:

• A professional website with contact information

• Genetic experts on staff

• Information about the test and the laboratory

• Answers to common questions

• A privacy policy statement

Privacy Risks

Some people are understandably wary of getting tested because of privacy issues. This is one reason it is so important to choose a reputable company. Your clients should know that the Genetic Information Nondiscrimination Act protects them from discrimination in health insurance and employment based on genetic test results.

Emotional Harm

The risks associated with lifestyle tests are a little less than with other types of DNA testing. For instance, a medical DNA test could uncover information that an individual has an increased risk for a serious disease. This can cause a lot of emotional distress.

For health and fitness tests, your clients still may have some poor emotional responses to their results. Results that are discouraging and indicate a client is going to struggle with weight loss and fitness can lead to a sense of hopelessness or even depression.

What you can do as a trainer or coach is prepare your clients for these kinds of results. Explain that even if the answers are disappointing, there is an upside: the results can help you better help them. Even if they have to work harder, they can still meet health and fitness goals with this personalized information.

Genetic testing is an improvement for health and fitness. Understanding nutrigenetics and nutrigenomics is an important part of your role as a coach and trainer. It will help you educate your clients and help them benefit from your ongoing expertise.

Learn everything you need to know to help clients train using personalized genetic information with the ISSA's DNA-Based Fitness Coach course.

References

1. Schulz, L.C. (2010, September 28). The Dutch Hunger Winter and the Developmental Origins of Health and Disease. Proc. Natl. Acad. Sci. USA. 107(39), 16757-758. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2947916/

2. Topol, E. (2019, March 2). The AI Diet. New York Times. Retrieved from https://www.nytimes.com/2019/03/02/opinion/sunday/diet-artificial-intelligence-diabetes.html