Introduction: physical growth patterns and nutritional status of children and adolescents living at a moderate altitude are not applicable for clinical assessment of growth for diverse populations around the world. Objective: a) to compare weight, height and body mass index (BMI) variables with CDC-2012 references; b) to verify if BMI and/or ponderal index (PI) are applicable to children living at a moderate altitude; and c) to propose percentiles to assess physical growth by age and sex. Methods: a total of 5,377 students, ranging in age from 6.0 to 17.9 years, were evaluated. The students were from two geographic regions of moderate altitude in Peru (2,320 meters) and Colombia (2,640 meters). Weight and height were measured. BMI and PI were calculated. Weight, height and BMI were compared with CDC-2012 references. Results: males showed lower weight and height from age 11 to 17.9 years compared to CDC-2012. Females weighed less than the reference from 9.0 to 17.9 years. Female height was lower from 6.0 to 14.9 years; however, from 15.0 to 17.9 years, values were similar to the reference. As for BMI, there were differences in both sexes (in males, from 15.0 to 17.9 years, and in females, from 12.0 to 17.9 years). Age, weight and height explained BMI: between R2 = 17 and 83 % in males, and in females between R2 = 24 and 85 %. These same variables influenced PI in a lower percentage in both sexes: for males (R2 = 0.01 to 49 %) and for females (R2 = 0.01 to 18 %). Conclusions: children and adolescents living at a moderate altitude in Peru and Colombia diverge from the CDC-2012 physical growth patterns. In addition, PI is a new alternative for estimating weight in relation to BMI. The proposed curves for weight, height, and PI by age and sex could have greater implications in the control of child health programs and in clinical and epidemiological practices.