Psychobiological factors influencing physical activity and body composition in young adults: Chronotype and food addiction.

Chronotype and food addiction are key psychobiological factors related to physical activity, dietary patterns, and body composition in young adults. However, their combined associations with body structure remain insufficiently explored. This study aimed to holistically examine the relationships of chronotype and food addiction with physical activity and body composition among university students. A total of 582 participants (294 women, 288 men; M = 20.78 ± 2.69 y) were assessed using a cross-sectional design. Chronotype was measured with the Morningness - Eveningness Questionnaire (MEQ), food addiction with the Yale Food Addiction Scale (YFAS), and physical activity with the Physical Activity Scale-2 (PAS-2). Body composition was evaluated using bioelectrical impedance analysis (BIA). Statistical analyses included descriptive tests, independent t-tests, correlation, and multiple regression. Physical activity showed a modest positive association with body mass index in the regression model (β = .198), while no direct relationship was observed with body fat percentage. Evening chronotypes demonstrated higher BMI and visceral adiposity compared with morning and intermediate types, indicating a less favourable adiposity profile. Although food addiction did not display a linear correlation with body composition, individuals reporting ≥3 symptoms showed slightly higher BMI values. In the final model, physical activity, chronotype, and food addiction collectively accounted for 8.7% of the variance in BMI (R2 = .087), underscoring their limited yet meaningful contribution. Overall, these findings suggest that body composition in university students is influenced more by behavioural rhythms and timing preferences than by energy balance alone.