Diet and physical activity education in school-aged children and young adolescents are in the focus of the modern healthcare and education system. The aims of our cross-section study were to estimate the prevalence of obesity in youth, and the significant correlation between nutrition status, health behavioural and biological markers. The sample size was 400 randomly selected school-aged children and adolescent from 14 to 18 years old. They were divided into two population groups of school-aged children (12-13 years old) and young adolescent (17-18 years). Standardized, non-quantitative Food Frequency Questionnaire (FFQ) and the International Questionnaire for assessment of Physical Activity (IPAQ-short version) were used as well as the anthropometric measurements: body weight and height, body mass index (BMI kg/m2) presented in percentile using the WHO Child Growth Standards. Statistical analysis was included descriptive statistics, Pearson Chi-square test and Logistic regression analysis using SPSS Statistics 17.0. In accordance with the distribution of Pearson Chi-square=16.94 (p<0.001), there was statistical significance between nutritional status of study participants in both, first and second study groups. Also, there was significant difference in high intensity sports activity between two groups (Pearson Chi-square=26.59; p<0.001). Sedentary behaviour had the highest influence on development of childhood obesity (Wald=2.81; p=0.09). Significant correlation was estimated between obesity and sweetness food (pasta, rise and potatoes), soft drinks, but drinking water had a protective effect. Prevention and treatment of pediatric overweight and obesity require systems-level approaches that include the skills of registered dietitians, sports coaches as well as consistent and integrated messages and environmental support across all sectors of society, especially educational sector. The next step is to develop an innovative “Skills for health” model including nutrition and physical activity education program in Macedonia.