[Dietary patterns related to cardiorespiratory autonomic activity in university students]

Introduction: heart-rate variability (HRV), respiratory-rate variability (RRV) and the pulse-respiration quotient (PRQ) reflect autonomic modulation, yet their relationship with university dietary habits remains understudied. Objective: to examine the association between dietary patterns and autonomic activity among university students. Methods: ninety-one young adults were classified, via factor analysis, into a healthy (PDS) or an unhealthy (PDNS) dietary pattern. From 5-min beat-to-beat (RR) and breath-to-breath (BB) recordings we extracted: high-frequency log power (HFlog), parasympathetic (PNS) and sympathetic (SNS) indices, stress index, mean RR interval (Mean RR), fractal exponents α₁ and α₂, Poincaré dispersion (SD₂), and the low- to high-frequency power ratio (LF/HF). For RRV we obtained mean breathing rate (BRmean) and BB deviation (SDBB); for PRQ we calculated mean PRQ (mPRQ). Student's t-, Mann-Whitney U-tests and Spearman correlations were applied (p ≤ 0.05). Results: fifty-three percent of participants followed the PDNS. In men, the PDS showed higher HFlog and α₁ ≈ 1. Within the PDS, lean animal products were linked to ↓SNS, ↓stress, ↓α₂ and ↑Mean RR; non-fat cereals to ↑PNS and ↓LF/HF in men; fruits-vegetables to ↓BRmean and ↑SDBB; legumes and canned fish to ↓mPRQ. In the PDNS, sugary drinks decreased PNS, HFlog and SD₂ but increased SNS in women, and raised stress and α₂ in men; fat-rich cereals elevated α₂. Conclusion: the PDS enhances vagal tone, fractal stability and cardiorespiratory synchrony, whereas the PDNS heightens sympathetic activity and lowers variability, particularly in women. These findings support early nutritional interventions that foster the PDS.