Tvarijonaviciute A, et al. - In this observational study, researchers sought to assess saliva use, as a non-invasive tool in epidemiological studies performed in school-age children, to capture metabolic changes correlated with BMI, dietary intake and physical activity in both boys (n = 69) and girls (n = 60). Study participants included 129 healthy children of ages between 8 and 12 years from three schools in a Mediterranean area of Spain. Findings reveal that in school-age children, biomarkers in saliva are capable of capturing variations in BMI, dietary habits and levels of physical activity. Saliva may be a useful, non-invasive and stress-free tool for gender-dependent assessment of metabolic markers of inflammation and/or metabolism related to BMI and lifestyle. Gender differences in serum glucose and TNFα were detected.