Precision Nutrition, a developing science
Research suggests that personalized precision nutrition promotes healthier, longer-lasting changes than conventional dietary guidance.
Culinary Medicine

by Lori A Smolin, PhDÂ and
Are you one of the eight out of ten Americans who says they would like to eat a healthier diet?.[1] If so, how do you plan on doing so? An internet search yields an endless assortment of diets claiming to be the most nutritious. Which one is best for you? In general, a healthy eating plan is one that will boost your health today and maintain it in the years to come.[2] The plan should also be affordable, appealing, and meet your social and cultural needs. Precision nutrition is an approach used to create a customized eating plan based on your genetic background, individual health markers, and lifestyle. If you were provided with such a plan, would you change your diet to follow it?Â
Â
General Guidelines for a Healthy Diet
A healthy diet provides the nutrients you need to optimize wellbeing while at the same time limiting dietary components that increase your susceptibility to disease. A variety of population-wide nutrition guidelines have been developed to help the general public select such a diet. The Recommended Dietary Allowances (RDAs), for example, offer goals for energy and nutrient intake that will meet the requirements of nearly all healthy individuals.[3] MyPlate and the Dietary Guidelines for Americans suggest food choices that make up a healthy eating plan.Â
While these nutrition guidelines can be helpful in planning a healthy diet for the overall population, they are not necessarily optimal for each individual. For example, what about that friend who can eat anything they want without gaining weight, while you gain weight seemingly just by looking at food. This contrast is because the response to food and nutrient intake varies among individuals. Research confirms that different people eating identical meals have different changes in blood glucose, triglycerides, and other metabolic parameters in response to the meals.[4] Our genetic make-up determines not only these metabolic differences but also our susceptibility to chronic diseases. For example, even when consuming a similar diet, African Americans have a higher risk of hypertension than Caucasian Americans and people who inherit familial hypercholesterolemia have a higher risk of developing heart disease than those who don’t.Â
Designing Your Healthiest Diet: A Personalized Precision Nutrition Approach
What you know about your health risks can help you plan a healthy diet and your health care providers can help tailor dietary recommendations based on your current intake, health history, and laboratory data, but such diet plans still rely on assumptions. For example, one would assume that if your grandfather died of a heart attack you would also be at high risk of heart disease. Precision nutrition, also known as personalized nutrition, is an emerging approach to designing the healthiest diet for you that is based on your genetic profile as well as other individual variables including your metabolic parameters, microbiome, health history, physical activity, and dietary habits. The dietary pattern recommended by precision nutrition has the potential to help prevent and treat chronic diseases to which you are susceptible.[5]Â Â
An internet search for precision nutrition will direct you to a number of programs that offer dietary recommendations based on an analysis of your DNA. These analyses look for variations in single genes associated with the risk for specific conditions. They can determine predispositions such as sensitivity to caffeine or alcohol or a propensity for weight gain or hypertension.[6,7] Participants in such a program receive a report showing which gene variations they have and recommending an eating plan based on these results. However, dietary recommendations based just on these DNA results have shortcomings. Having a gene variant for a particular disease does not mean you will develop the disease or whether a change in diet would be beneficial. The genetics of nutrient metabolism and disease is more complicated than single gene variations. Identifying a genetic variant doesn’t explain the extent to which that gene is expressed, or which other genes interact with it to determine the overall risk of developing a specific disease.[8.9] In addition, environmental, biological, genetic, and socioeconomic components also impact how genes affect health. Â
So, while DNA analysis offers insight into your risk for nutrition-related diseases, a more comprehensive precision nutrition approach is needed to accurately determine individual responses to food and dietary patterns.[10] This approach interprets gene interactions within the context of other individual factors such as dietary and health history, laboratory values, and microbiome composition. So, for example, if your genetic profile shows you have a propensity for elevated blood cholesterol, linking this information with your cholesterol values and an analysis of your typical diet, will help determine if you need to change your diet to reduce your heart health risk. If you have elevated blood glucose, a profile of the types of bacteria that live in your microbiota can guide dietary recommendations to promote changes in your microbiome composition to improve blood glucose control. [11] This more comprehensive form of precision nutrition is still a developing science. The NIH Nutrition for Precision Health Initiative is collecting this type of data from participants across the country and using artificial intelligence to analyze it and develop algorithms that predict responses to dietary patterns and generate precision nutrition advice. As this science develops, the analyses currently available will also likely advance and so will our ability to predict your healthiest diet.Â
Will Precision Nutrition Improve Your Diet?Â
If you were prescribed a diet that eliminates your favorite foods, would you follow it? Individual eating patterns are engrained and can be difficult to change. Would you be more likely to change your diet if you had access to precision nutrition advice rather than just general nutrition guidelines? For some, knowing their genetic predispositions may reduce motivation to make changes because they feel doomed to develop these conditions. [9] For others personalized advice might inspire them to change their diet to reduce risk. There is some research to suggest that individuals who are offered dietary advice based on their individual DNA analysis make healthier and longer lasting changes than when offered conventional advice.[12] One study showed that a personalized nutrition approach resulted in greater improvements in heart health risk factors than standard dietary guidance.[13] While most research suggests a diet personalized by genetic testing yields only modest dietary changes, even small improvement such as eating more fruits and vegetables can have a significant impact on health. [9] As the science advances, will recommendations based on more comprehensive precision nutrition promote greater dietary improvements?Â
Are We Ready for Personalized Precision Nutrition?

We are not yet able to fill our plates based on comprehensive precision nutrition prescriptions and unfortunately many of us are not even filling our plates based on the general recommendations for a healthy diet. Even though precision nutrition advice will target our individual needs better than general guidelines, the question remains: Are we willing to change our diet for our long-term health? [14]
References
[1] American Heart Association. Alarming trends call for action to define the future role of food in nation’s health. Published June 10, 2024. https://newsroom.heart.org/news/alarming-trends-call-for-action-to-define-the-future-role-of-food-in-nations-health
[2] U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. 9th Edition. December 2020. https://www.dietaryguidelines.gov. Accessed October 3, 2024.
[3] What are Dietary Reference Intakes? In: Institute of Medicine (US) Food and Nutrition Board. Dietary Reference Intakes: A Risk Assessment Model for Establishing Upper Intake Levels for Nutrients. Washington (DC): National Academies Press (US); 1998.
https://www.ncbi.nlm.nih.gov/books/NBK45182/#. Accessed October 3, 2024.
[4] Berry SE, Valdes AM, Drew DA, et al. Human postprandial responses to food and potential for precision nutrition [published correction appears in Nat Med. 2020 Nov;26(11):1802. doi: 10.1038/s41591-020-1130-y]. Nat Med. 2020;26(6):964-973. doi:10.1038/s41591-020-0934-0.
[5] Voruganti VS. Precision nutrition: Recent advances in obesity. Physiology (Bethesda). 2023;38(1):0. doi:10.1152/physiol.00014.2022.
[6] Guasch-Ferré M, Dashti HS, Merino J. Nutritional genomics and direct-to-consumer genetic testing: an overview. Adv Nutr. 2018;9(2):128-135. doi:10.1093/advances/nmy001.
[7] de Toro-MartÃn J, Arsenault BJ, Després JP, Vohl MC. Precision nutrition: a review of personalized nutritional approaches for the prevention and management of metabolic syndrome. Nutrients. 2017;9(8):913. Published 2017 Aug 22. doi:10.3390/nu9080913.
[8] Fuchsberger C, Flannick J, Teslovich TM, et al. The genetic architecture of type 2 diabetes. Nature. 2016;536(7614):41-47. doi:10.1038/nature18642.
[9] Mullins VA, Bresette W, Johnstone L, Hallmark B, Chilton FH. Genomics in personalized nutrition: can you "Eat for your genes"?. Nutrients. 2020;12(10):3118. Published 2020 Oct 13. doi:10.3390/nu12103118.
[10] National Institutes of Health. NIH Launches Largest Precision Nutrition Research Effort of Its Kind. May 16, 2023.
https://allofus.nih.gov/news-events/announcements/nih-launches-largest-precision-nutrition-research-effort-its-kind. Accessed September 8, 2024.
[11] Harvard T.H. Chan School of Public Health. The Nutrition Source. Precision Nutrition. https://nutritionsource.hsph.harvard.edu/precision-nutrition/. Accessed September 2, 2024.
[12] Celis-Morales C, Livingstone KM, Marsaux CF, et al. Effect of personalized nutrition on health-related behaviour change: evidence from the Food4Me European randomized controlled trial. Int J Epidemiol. 2017;46(2):578-588. doi:10.1093/ije/dyw186.
[13] Bermingham KM, Linenberg I, Polidori L, et al. Effects of a personalized nutrition program on cardiometabolic health: a randomized controlled trial. Nat Med. 2024;30(7):1888-1897. doi:10.1038/s41591-024-02951-6.
[14] Kirk D, Catal C, Tekinerdogan B. Precision nutrition: a systematic literature review. Comput Biol Med. 2021;133:104365. doi:10.1016/j.compbiomed.2021.104365.
Comments