Participants in this group receive a genetic hair analysis and a personalized nutritional follow-up based on the results. The aim is to assess whether the nutritional intervention modifies relevant genetic or biochemical markers after the intervention period.

Participants in this group receive a genetic hair analysis and are provided with the results only, without any nutritional follow-up. This group serves as a comparison to evaluate the effect of the nutritional intervention in the experimental group.

Participants in the experimental arm will receive a individual nutritional follow-up based on their epigenetic hair analysis results. This includes dietary guidance, recommendations tailored to genetic markers, and periodic consultations with a nutritionist over 4 weeks and continuous availability to clarify doubts via email . The aim is to evaluate changes in genetic expression or health biomarkers after the intervention period.

This outcome evaluates the correlation between the nutritional intervention and functional epigenetic status, assessed through the S-Drive optimization report. The measurement tool is the S-Drive system (Cell Wellbeing, Germany), a non-invasive device that analyzes resonance frequency patterns from hair follicle samples using proprietary bioinformatic algorithms. The report classifies physiological function into 12 domains related to nutritional metabolism (e.g., micronutrients, oxidative stress, circulatory function), assigning ordinal values to each: "not flagged" (0), "to be considered" (1), "advisable" (2), or "priority" (3). Two derived quantitative variables will be analyzed: (1) the number of domains classified as "priority" (unit: count, range: 0-12), and (2) the cumulative optimization score summing the ordinal ratings (unit: score, range: 0-36). These biofrequency will be used to assess within-subject changes and between group correlations from baseline to 90-day follow-up.

This outcome assesses adherence to the Mediterranean dietary pattern using the validated 14-item PREDIMED questionnaire (PREvención con DIeta MEDiterránea). Each item is scored as 0 (non-compliance) or 1 (compliance), for a total score ranging from 0 to 14. Higher scores indicate better adherence. The unit of measurement is the total PREDIMED score. A score ≥9 is considered high adherence. This variable will be measured at baseline and after the 90-day intervention to evaluate correlations between the individualized nutritional guidance and improvement in diet quality in the experimental group compared to the control group.