Childhood obesity has been associated with altered blood lipids and bad eating habits. In this cross-sectional study, we assessed cardiorespiratory fitness and metabolic health markers in regard to weight status and dietary habits in schoolchildren. In 134 children (6-11 years), we conducted: (1) Anthropometry, namely z-score BMI (z-BMI), waist-to-height ratio (WHtR), and body composition analysis. (2) Measurements of handgrip strength (HGS), resting metabolic rate (RMR) and VO2max. (3) Quantification of blood lipids and antioxidant vitamins A, E, C. (4) Eating breakfast assessment. About 35% of children were overweight/obese. The z-BMI positively correlated with WHtR (r = 0.637, p < 0.001), and adversely correlated with fat-free mass (r = -0.728, p < 0.001) and vitamin E (r = -0.286, p < 0.001). RMR and VO2max were greater in normal weight children compared to those with overweight/obesity (p < 0.001). HGS did not differ between these groups, but was negatively correlated with dyslipidemia as shown by TG/HDL-C ratio (r = -0.224, p = 0.037). According to regression analysis, eating breakfast routinely at home was positively associated with RMR and adversely associated with z-BMI. Hence, regular breakfast consumption at home may improve RMR in kids. Cardiorespiratory fitness and physical strength are key modulators of metabolic health in Greek children added to a social determinant of health i.e., eating breakfast at home.
Keywords: antioxidant status; breakfast at home; cardiorespiratory fitness; handgrip strength; metabolic health; primary school children.