The goal of precision nutrition is for everyone to have information on what, when, why, and how they can eat to stay healthy. This information would be unique to each person and based on one’s body, lifestyle, and circumstances. The science of precision nutrition is in an early stage, explains Holly Nicastro, PhD, MPH, but it holds promise for being able to match individuals to the eating pattern that works best for them.

Q: What is the link between eating patterns and risk for chronic diseases, particularly type 2 diabetes?

A: Consuming foods and beverages with high amounts of added sugars, sodium, and saturated fat, or eating too much in a way that leads to weight gain, can increase your risk for type 2 diabetes or other chronic diseases. But the good news is that positive dietary habits like eating whole grain foods, fruits and vegetables, fiber-containing foods, and micronutrient-rich foods, and avoiding things like added sugars, sodium, and saturated fats, can decrease your risk.

Q: Does healthy or unhealthy eating have the same impact on everyone?

A: No. The nation offers dietary recommendations, the Dietary Guidelines for Americans, 2020–2025, but these are broad. While the guidelines provide population-based recommendations, a one-size-fits-all approach to diet doesn’t always cut it, because in virtually every nutrition study we see some degree of individual variability in response to a given diet. For example, when people at risk of type 2 diabetes are advised to follow the Diabetes Prevention Program Lifestyle Change Program, we expect to see outcomes improve. However, the amount of weight lost or the change in glucose response does vary by individual patient.

Q: What are the different factors that might contribute to this variability?

A: Age, sex, genetics, meal timing, and the makeup of one’s microbiome, or gut bacteria, can all contribute. So can a woman’s pregnancy, lactation, or menopause status. These are just some of the variables that we know about. We still need to discover and better study other factors that might also contribute, such as the environment or life experiences like stress. And, we need to study all of these factors holistically, instead of testing one or a few factors at a time.

Q: How can precision nutrition help people find the eating pattern that best supports their health?

A: When NIH uses the term “precision nutrition,” we’re talking about the goal of individualized and actionable dietary recommendations that will help people decide what, when, why, and how to eat, so that they can optimize their health or quality of life. For a person with type 2 diabetes, for example, precision nutrition may mean following a dietary pattern that minimizes blood glucose spikes and crashes. But at this point, we don’t have a test that an individual can take to figure out exactly how they can eat to optimize health.

Q: How is precision nutrition being used in clinical practice today?

A: In terms of individualized and actionable dietary recommendations, we tailor advice and recommendations all the time. As an example, the Dietary Guidelines for Americans stratify recommendations by age and sex. Pregnant and lactating women have additional recommendations for minerals and nutrients like iron and choline; older adults also have different dietary recommendations.

We also tailor dietary guidance based on disease status. Think about celiac disease, where a person can’t tolerate gluten; we wouldn’t give them the same dietary recommendations as somebody else of their same age, weight, or sex. We tailor dietary recommendations to patients with diabetes when we advise them to limit added sugars and stick to consistent timing of meals. So, we’re doing precision nutrition all the time, but the future of precision nutrition would involve tailoring dietary advice based on a more comprehensive list of factors than what we currently use like age, sex, or disease status.

Health care professionals today also take a precision approach with how they educate their patients and how they recommend changes patients can make in their lives. They might consider their patient’s socioeconomic status, family situation, and other factors.

Right now, the gold standard for nutrition education—what’s been studied, what’s covered by Medicare—is group counseling combined with individualized counseling. But instead of just saying, “Okay, follow the standardized program,” maybe we can use some of the factors about the individual to decide how we are going to make this or any other recommendation. I’ll use myself as an example. I’m in my thirties with two kids and a husband at home. You can’t just tell me to follow a specific diet without considering the needs of my whole family. So maybe a better approach would be to provide me with recipes that feed a whole family or that are kid friendly.

Q: What improvements will precision nutrition bring to diabetes care?

A: With diabetes, I can envision being able to accurately predict individual blood glucose responses to different foods, dietary patterns, or dietary strategies. This would involve several steps: determining the factors that are most important; predicting individual responses to different foods, food groups, and dietary patterns; developing the tailored plan for an individual; and finding the most effective way to educate that individual on how to follow the recommendations.

This tailored approach could be implemented with people who have prediabetes or are at high risk of getting diabetes. Precision medicine could also potentially help in longer-term management of diabetes or possibly reversal of type 2 diabetes. I am hopeful that this approach can continue to be rigorously studied and more widely adopted in the next several years.

Q: What needs to be done to refine and tailor nutrition guidance to patients?

A: We need to identify the most important out of hundreds of thousands of potential predictors: genes, microbiome signatures, metabolic fluxes over time, subjective measures of a person’s experience, and other complexities. This will require very, very, very large datasets from a larger study than has been done before, one that enrolls a very large number of people and ensures diversity among the people being studied.

Using artificial intelligence (AI), we could integrate multimodal data to produce the algorithms that determine how an individual would respond to a given food or dietary pattern. Another benefit of an AI approach is that it could help to identify predictive factors for healthy or unhealthy outcomes that may have smaller effects on their own, but in combination with other factors, could contribute to variability. So maybe there’s a certain gene that on its own doesn’t predict response to treatment, but if you see this genetic signature in females over the age of 50 who have also a specific microbiome signature, that’s when you might get a bigger signal.

Q: How is the NIH research project, All of Us, helping build knowledge on precision nutrition?

A: The All of Us Research Program is a national precision medicine effort. We’re building the largest and most diverse database of health information of its kind. This resource is going to be available to all researchers, and we’re aiming to enroll a million or more participants.

Q: You’re the coordinator for an NIH initiative, powered by All of Us, called Nutrition for Precision Health. What is that?

A: Nutrition for Precision Health will be the first major ancillary study to All of Us, with about 10,000 participants. Its goal is to develop algorithms to predict individual responses to foods and dietary patterns, and it will leverage the participant cohort and the infrastructure to expand data collection and drive new discoveries.

Nutrition for Precision Health will be issuing research grants early in 2022 and will focus on three exciting opportunities. The first opportunity is identifying and strengthening the evidence base for predictive variables, for example, in the genome or microbiome or in relation to behavior and social determinants of health. The second opportunity is using artificial intelligence and machine learning to predict individual responses to different foods, dietary patterns, or dietary advice, and continuously improving the accuracy of those predictions.

A third exciting opportunity is implementation science—the study of methods to promote the adoption of tailored or personalized approaches. We’re not there yet, because we need to first build the evidence base for predictive factors and responses. However, I think there will be some unique opportunities for getting people to better adhere to dietary advice when we use precision approaches.

Q: How can health care professionals support this research?

A: Health care professionals can refer their patients to join the All of Us Research Program. People can sign up now through funded health care provider organizations or sign themselves up online. (Nutrition for Precision Health will begin enrollment in a few years.)

All of Us participants provide information via surveys and linkages to their electronic health records. Some physical measurements are taken in person, and patients will submit a blood sample for genomic information. Privacy of participant data is one of the core values of the All of Us Research Program, and there are huge efforts to earn and keep the trust of the participant. Joining the All of Us Research Program can be a very motivating and exciting way for patients with diabetes to focus on their own health while also helping to build the knowledge base for a precision nutrition approach to diabetes care.

How do you currently apply the concept of precision nutrition when working with patients who have diabetes? Tell us below in the comments.