Objective: In the last decades, the prevalence of overweight and obesity in childhood has been increasing worldwide at an alarming rate [1]. The negative impact of this pandemic is reflected on children's health and is perpetuated in their adulthood [2]. It is recognized that preventive strategies are priority in fighting childhood obesity, and that schools are a preferential environment for this approach [1-3]. Our aim was to evaluate a cohort of elementary school students to understand the need for preventive community nutrition programs. Material and methods: This were a cohort study with two points of evaluation in time, enrolling students of two elementary schools (Escola B asica Rosa Colaço and Escola B asica Chegadinho, Almada, Portugal). Students were annually evaluated through anthropometric measures, for two years. Data from anthropometric evaluation were gathered in WHO Anthro Plus, and results are presented according to WHO z-cores. Since 2016, this group of schools has been working to increase the physical activity of these students through a project supported by the Portuguese Ministry of Education and with scientific consulting of Nutritionists from Egas Moniz. However, the project does not include regular support of a nutritionist to educate and treat this vulnerable population. Results: In 2016-2017, 271 students were evaluated (133 females). Prevalence of obesity and overweight in Escola B asica Rosa Colaço was 7.4% and 22.1%, respectively. During the same period, in Escola B asica Chegadinho, that prevalence was 8.9% and 23.0%, respectively. Also, prevalence of underweight was 2.3% in Escola B asica Rosa Colaço and 0.7% in Escola B asica Chegadinho. In 2017-2018, 313 students were evaluated (147 females). Despite of a regular schedule for physical activity in these elementary schools implemented at the end of 2017, in 2017-2018, prevalence of obesity and overweight in Escola B asica Rosa Colaço was 12.7% and 26.6%, respectively; and in Escola B asica Chegadinho, that prevalence was 20.0% and 22.6%, respectively. This represent a total increase in obesity prevalence of 5.3% in Escola B asica Rosa Colaço, and of 11.1% in Escola B asica Chegadinho. Conclusion: Our results reveal a shocking reality in these two elementary schools. Also, this high prevalence of both obesity and overweight in children under the age of 10, in spite of the implementation of a regular program of physical activity in schools, evidence that community programs should include regular nutrition education and advisory. Our results also reinforce the need for the inclusion of Nutritionists in schools to work together with students, teachers, and families.