2.3.1. Physical growth
All anthropometric measures were taken by the same filed worker following standardized procedures in a local school classroom. Standing height was measured to 1 mm precision using a stadiometer (SZG-210, Shanghai JWFU Medical Apparatus Corporation) and weight after losing heavy clothes was measured to nearest the 0.1 kg (BC-420, Tanita Corporation, Tokyo, Japan). Height-for-age and sex 