Precision nutrition is the practice of customizing dietary recommendations based on a person’s unique biology, lifestyle, and environment. It is an emerging field that tailors diet and lifestyle to an individual’s genetics, microbiome, and blood sugar levels. This future-forward topic promises customized health solutions to promote longevity and overall wellness. It utilizes genetic testing, microbiome analysis, wearable data, and AI-driven apps to provide personalized diet plans based on physiological responses to diet and lifestyle.
These are all admirable health goals. However, individuals should proceed with caution. Precision nutrition is still in its infancy, and not only can these tests be expensive, but they may also compromise health if not guided by an accredited clinician.
Registered Dietitians (RDs) have been delivering medical nutrition therapy for decades. So how is precision nutrition different? Medical nutrition therapy is an evidence-based nutrition treatment plan designed by a registered dietitian to manage medical conditions. It relies on clinical assessments, nutrition diagnoses, and counseling techniques to help individuals meet their health goals.
Many apps and platforms market “personalized diets,” but not all are backed by peer-reviewed science. RDs can distinguish between validated tools and those still experimental, ensuring patients invest time and money wisely. With advanced degrees in nutrition science, RDs have the expertise to interpret findings in the context of medical history, lab values, and lifestyle. Without this expertise, clients risk misapplying the data. Misuse of data can lead to nutrient deficiencies, disordered eating, or ignoring medical conditions. RDs bridge the two: they can use precision tools to enhance clinical care, not replace it.
Another concern is the exploitation of vulnerable individuals, such as those who lack health insurance. If enhanced Affordable Care Act (ACA) premium tax credits expire, an estimated 4.8 million people will lose coverage in 2026. For people without insurance, these platforms can feel like a lifeline, but without regulation and professional guidance, they risk becoming exploitative. For instance, DNA tests, microbiome kits, and continuous glucose monitors are marketed as “affordable alternatives” to medical care, yet they often cost hundreds of dollars out-of-pocket. Many platforms also use monthly fees for “personalized coaching” or app access. Without insurance coverage, people may overcommit financially, believing these services substitute for medical care. Finally, health data from uninsured users may be sold to third parties (e.g., advertisers, insurers, or employers). Without protection, this can reinforce inequities and even lead to discrimination.
The two technologies I hear most about from my patients are continuous glucose monitoring (CGM) and gut microbiome testing. CGMs are strongly evidence-based for people with diabetes, but their use in the general population is still experimental. Research shows they can reveal individual differences in blood sugar responses, but there is not yet enough long-term evidence to recommend them for routine use outside of clinical settings. Unlike diabetes care, there are no clinical protocols for CGM use in healthy individuals. Without professional guidance, users may over-restrict foods or misinterpret normal glucose fluctuations.
Regarding microbiome testing, there are no universally accepted “healthy ranges” for microbiome composition, making results difficult to interpret in a medical context. Additionally, our gut microbiota is massive, dynamic, and constantly changing, with little standardization in testing or interpretation. According to an international review published in The Lancet in February 2025:
“There is growing interest in the potential exploitation of the gut microbiome as a diagnostic tool in medicine, but evidence supporting its clinical usefulness is scarce. An increasing number of commercial providers offer direct-to-consumer microbiome diagnostic tests without any consensus on their regulation or any proven value in clinical practice, which could result in considerable waste of individual and health-care resources and potential drawbacks in the clinical management of patients.”
We are simply not there yet.
The appeal of precision nutrition lies in its promise of personalized health solutions at a time when people are increasingly skeptical of “one-size-fits-all” diet and lifestyle interventions. Wearables, apps, and tests give individuals a sense of control over their health by providing real-time feedback. In a time when many of us are stressed about life’s uncertainties, it is easy to see why people find this approach appealing.
If you do want to try one of these devices for fun, please work with a credentialed clinician, such as a registered dietitian, to interpret your results and guide your behaviors. RDs are more accessible than ever and accept many insurance carriers. To find one in your area, visit eatright.org.
Written by Barbara Broggelwirth, MS, RDN, CDN