Nutritional habits, inhibitory control, and emotional reactivity to healthy and unhealthy food cues in non-obese female students: insights from heart rate variability

Background: Research shows that the nutritional habits of university students do not follow the national recommendations. While most studies have focused on the increased risk of overweight/obesity, avoiding unhealthy food or maintaining a normal weight does not necessarily result in a regular consumption of healthy essential nutrients. Methods: The present study was aimed at investigating the interplay between emotional reactivity and inhibitory control in 42 non-obese female students exposed to healthy (fish/lean meat, fruit/vegetables) and unhealthy (savory and sweet junk food) food pictures, after an average fasting of 7.5 h. Resting heart rate variability (HRV) was assessed as a physiological index of self-regulation, exploring its association with emotional reactivity and inhibitory control, as well as its predictive role in nutritional habits. We measured valence, arousal and craving during a free viewing time task and assessed inhibitory and attentional control through an emotional Go/NoGo task. Hunger, nutritional habits and frequency of physical activity were also collected. Results: Unhealthy foods elicited higher pleasantness, arousal and craving than healthy foods, indicating stronger appetitive motivation. Emotional reactivity was predicted by hunger or fasting duration as a function of food type. Higher HRV predicted slower reaction times to Go stimuli for all food types except fruit/vegetables. HRV and physical activity negatively predicted the habitual consumption of sweet junk food and positively predicted that of fruit/vegetables. Conclusion: Our results provide novel insights into the mechanisms underlying dietary self-regulation in non-obese female students, highlighting the significant role of resting HRV and physical activity in promoting healthy dietary choices and limiting junk food intake.