Biofrequency-Guided Nutrition in Spanish Adults

Functional Epigenetic Optimization

Functional status will be assessed with the S-Drive optimization report, which analyzes resonance frequency patterns from hair follicle samples using proprietary algorithms. The report classifies each participant's physiological functioning into 12 domains grouped into four categories: (1) Micronutrient indicators (vitamins, minerals, amino acids, fatty acids, antioxidants); (2) Systemic physiological indicators (immune system, gut health, circulatory function); (3) Epigenetic and environmental stressors (EMF, ELF radiation, toxins, additives); and (4) Dietary guidance (food choices, hydration, supplementation). Each domain is rated on four qualitative levels: "not flagged" (0), "to be considered" (1), "advisable" (2), and "priority" (3). Two derived scores will be analyzed: the total number of "priority" domains and a cumulative optimization score (0-36). These will be used to assess within-subject changes and between-group differences from baseline to follow-up.

Anthropometric Data

Anthropometric data, including current body weight (in kilograms) and height (in centimeters), will be self-reported by participants. These measurements will be used to compute body mass index (BMI), which is calculated by dividing weight in kilograms by the square of height in meters (kg/m²). BMI categories will be defined in accordance with World Health Organization (WHO) standards: BMI \< 18.5 ("underweight"), 18.5 ≤ BMI \< 24.9 ("normal weight"), 25 ≤ BMI \< 29.9 ("overweight"), 30 ≤ BMI \< 34.9 ("obesity class I"), 35 ≤ BMI \< 39.9 ("obesity class II"), and BMI ≥ 40 ("obesity class III") (Weir \& Jan, 2023). Although self-reported measurements may be susceptible to bias, previous research indicates that self-reported BMI estimates are generally valid in adult populations (Stommel \& Schoenborn, 2009).

24-Hour Movement Behaviors

Physical activity across work/school, transport, and leisure will be assessed with the validated PAS-2.1S (Valles-Medina et al., 2021). The scale has nine items: six on daily activities (weekday/weekend sleep, sedentary behavior, active physical activity, leisure, commuting) and three on weekly activities. Sleep duration is self-reported; sedentary behavior covers commuting by car/public transport and screen/reading time. The weekly subscale records light (e.g., walking), moderate (e.g., gardening), and vigorous (e.g., running) activities. Activity intensity, based on METs (Ainsworth et al., 2000), includes values such as sleep (0.9), sitting work (1.5), light activity (3.0), and vigorous activity (6.0). Daily work/transport METs are multiplied by five; sleep/leisure by seven. Missing daily hours (\<24) are doubled. Total METs from daily and weekly activities yield total energy expenditure.

Adherence to the Mediterranean diet (MedDiet)

Adherence to the Mediterranean diet (MedDiet) will be measured using the PREvención con DIeta MEDiterránea (PREDIMED) questionnaire (Martínez-González et al., 2012). Participants will report the frequency or quantity of consumption of 12 core dietary components (e.g., fruits, vegetables, olive oil, nuts) and two related dietary habits. The 14-item tool assigns binary scores (0 or 1) to each component, with total scores ≥9 indicative of high adherence to the MedDiet.

Tobacco smoking

Tobacco use will be assessed with two questions. First, participants will be asked: "Have you ever smoked tobacco in your lifetime?", with response options ranging from (a) never to (g) 30 times or more. Second, adolescents will be asked about current smoking frequency: (a) I do not smoke, (b) less than once a week, (c) more than once a week but not daily, and (d) every day.

Sociodemographic Data

Participants will provide self-reported information regarding their sex and age. Data will also be gathered on their current engagement in educational pursuits, employment status, participation in remunerated activities, and their specific occupation. Additionally, participants will be asked to indicate the primary reason for their most recent visit to primary care services. Educational attainment will be categorized as follows: (a) incomplete primary education (\<6 years), (b) completed primary education (6 years), (c) incomplete secondary education (\<4 years), (d) completed secondary education (4 years), (e) incomplete higher education (\<2 years of baccalaureate studies), and (f) completed higher education (2 years of baccalaureate studies or a bachelor's degree).