In a world where performance—whether physical, cognitive, or emotional—is increasingly valued, nutrition becomes a key ally. But not just any kind of nutrition: rather, a personalized approach that takes into account sex, age, lifestyle, and even genetic profile. What works for an active child may not work for an adolescent undergoing intense hormonal development or for an adult woman with a demanding daily routine. Personalized nutrition aims precisely at this: providing the body with what it needs, when it needs it, and in the most appropriate form.

Why general recommendations are no longer sufficient

For many years, nutritional advice was framed in universal terms: “eat five servings of fruits and vegetables a day,” “avoid saturated fats,” “iron boosts energy.” Reality, however, is far more nuanced. Our bodies do not process nutrients in the same way. Some individuals absorb iron very efficiently, while others require constant supplementation. Some experience an energy boost from caffeine, while others feel more fatigued or anxious.

Modern science explains these differences through nutrigenetics and nutrigenomics—fields that study the interaction between genes and nutrients. In essence, they build a bridge between DNA and the plate, fundamentally changing the rules of nutrition and performance.

Micronutrients: small details, major impact

Micronutrients—vitamins and minerals—are often overlooked in favor of proteins or carbohydrates. Yet their role in performance is substantial, especially when genetic influences are taken into account:

  • Vitamin A is vital for vision and coordination—skills essential in sports requiring rapid reactions. Some individuals have a reduced ability to convert beta-carotene into active vitamin A (retinol) due to genetic variations (such as rs11645428 in BCMO1). These individuals may require direct sources of vitamin A, particularly if they follow a vegan diet.
  • Iron supports oxygen transport and endurance. Variations in genes such as TMPRSS6, TFR2, or HFE may indicate whether a person is prone to iron deficiency anemia or, conversely, iron overload. In female athletes, menstruation and restrictive diets further increase the risk of deficiency, directly affecting performance.
  • Folate and vitamin B12 influence DNA synthesis, red blood cell formation, and muscle function. Mutations in the MTHFR gene (e.g., the TT genotype at C677T) may lead to hyperhomocysteinemia, which is associated with impaired muscle recovery and increased cardiovascular risk. Additionally, variations in the FUT2 gene can affect vitamin B12 absorption, a nutrient essential for tissue oxygenation.

Macronutrients and body composition: it’s not just about calories

Vitamins are not the only factors that matter. Macronutrients—proteins, carbohydrates, and fats—directly influence body composition, energy levels, and physical output.

For example:

  • Proteins are essential for building and maintaining muscle mass, but their absorption and utilization can vary genetically.
  • Carbohydrates may be the ideal fuel for some athletes, while others—due to genetic factors—may perform better on moderate- or lower-carbohydrate diets.
  • Fats influence inflammation, hormonal health, and neuronal function, and the optimal omega-3 to omega-6 ratio may differ from one individual to another.

Different needs at each stage of life

Childhood and adolescence

During these stages, the body is in a phase of rapid growth. Bone mass, muscle tissue, and nutrient reserves are being built. Nutrition must be nutrient-dense rather than merely calorie-dense, and personalization is important to prevent deficiencies. Girls, for instance, face a higher risk of iron deficiency after the onset of menstruation.

Active adults

At this stage, goals may vary: weight maintenance, weight loss, muscle gain, or performance enhancement. A personalized nutrition plan can make the difference between stagnation and progress. Understanding one’s genetic profile, for example, may reveal how well caffeine is metabolized or whether higher doses of vitamin D are needed to support bone health and immune function.

Elite athletes

Here, every detail counts. Iron supplementation, optimal vitamin D dosage, carbohydrate metabolism capacity, or lactose sensitivity can all influence recovery, training capacity, and injury risk. Genetic testing becomes a valuable competitive tool, but its interpretation must be guided by qualified professionals.

Limitations and responsibility

Despite its promise, personalized nutrition is not a magic formula. At present, not all genetic variants translate into clear recommendations or precise dosages. Moreover, genetic testing should never replace clinical evaluation or consideration of overall lifestyle.

It is essential that this information be integrated responsibly, under the guidance of a specialist (nutritionist, physician, or pharmacist trained in nutrigenetics). Personalized nutrition means a holistic approach—considering sex, age, body weight, food preferences, physical activity, sleep habits, stress, and, yes, genetic profile.

Instead of a conclusion

Personalized nutrition opens a new pathway toward optimal performance at any age—whether we are talking about children discovering sports, developing adolescents, active adults, or elite athletes.

By integrating genetic profiling into dietary planning, we can build nutritional strategies that are more effective, more tailored, and, most importantly, more motivating. Because when you know what works for you, you become more mindful of your choices—and closer to the results you seek.

Performance begins on the plate—and the key lies in the genes.

Bibliography

Guest NS, Horne J, Vanderhout SM, El-Sohemy A. Sport Nutrigenomics: Personalized Nutrition for Athletic Performance. Front Nutr. 2019 Feb 19;6:8. doi: 10.3389/fnut.2019.00008., https://pmc.ncbi.nlm.nih.gov/articles/PMC6389634/

Sutehall S, Pitsiladis Y. Personalized Nutrition for the Enhancement of Elite Athletic Performance. Scand J Med Sci Sports. 2025 Apr;35(4):e70044. doi: 10.1111/sms.70044. https://pmc.ncbi.nlm.nih.gov/articles/PMC11958001/

Faizan U, Rouster AS. Nutrition and Hydration Requirements In Children and Adults. [Updated 2023 Aug 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK562207/