Socio-economic status modulates the link between vagal tone and chocolate consumption

Socio-economic status (SES) correlates with patterns of food consumption, yet the underlying physiological mechanisms remain unclear. This study examines how SES modulates the relationship between vagal tone, a physiological marker of self-regulation, and chocolate consumption. Different hypotheses about how SES may be linked to vagal regulation of chocolate consumption were put to a test in a laboratory study with a socio-economically diverse group of students ( n = 96). Vagal tone was assessed using an index of heart rate variability (HRV–HF) measured at rest (baseline) and during acute stress. Participants' chocolate consumption was measured using a bogus taste test. The results showed that socio-economic status interacted with vagal tone to influence chocolate consumption. Findings for both subjective and objective indicators of SES converged in showing that vagal tone predicted chocolate consumption among higher SES participants, with higher vagal tone associated with lower chocolate consumption. No such relationship was found in lower SES participants, suggesting a dissociation between vagal regulation and eating behaviour in this group. These findings highlight the importance of considering autonomic regulation in understanding socio-economic disparities in dietary behaviours. • SES modulates the link between vagal tone and chocolate consumption. • Vagal tone is associated with chocolate consumption in higher SES participants. • Vagal tone is dissociated with chocolate consumption in lower SES participants. • Socio-economic disparities are apparent in internal regulation of eating. • Findings suggest new avenues for addressing SES disparities in eating.