The lack of population-level data on growth and development of children and adolescents in Ecuador, and the existence of previous data suggesting an alarming increase in the numbers of children presenting overweight or obesity justifies the present cohort study which includes all pupils of municipal schools of Quito aged 9 to 17 years. Follow-up will continue for a minimum of 7 years. This will allow determining the evolution of prevalence of these phenomena and their trends as well as other indices, both physiological and family-related customs, in order to plan appropriate preventive interventions. The present cross-sectional study includes 21 municipal schools, grouped into four health zones, each of which depends on a health centre, also municipal, and which are responsible for the health of pupils in these schools. Of the 6964 pupils studied, 18.7% suffer overweight and 7.9% obesity: 19.3% and 9.7% respectively in boys, compared to 18.2% and 5.4% in girls. The study also assesses family characteristics, degree of sedentarism and nutritional habits: 62.3% declared living in a nuclear family, and 60.5% declared their families to be in the "adolescent" lifecycle stage; 91.9% of pupils were sedentary while 5.4% (CI 95% 4.87 -5.94) reported not eating breakfast every day.

(OR adjusted : 1.79;.Conclusions: agreement between parents and their children demonstrated discordance, but did not influenced on excess weight.