Evolution of the nutritional situation of indigenous and non-indigenous Chilean schoolchildren

Background: Latin American countries show accelerated but ethnically or socially differentiated changes in their epidemiological profiles. Aim: The present study examined the evolution of the nutritional situation (1997-2005) in Chilean schoolchildren as related to ethnical origin (Mapuche). Subjects and methods: Using official databases, stunting (height/age - 2 z-scores), undernutrition (body mass index (BMI) - 2 z-scores) and obesity (BMI 95 percentile) were ascribed in first-grade schoolchildren. Ethnic groups were assigned by native parents' surnames (none, one and two). Results: Based on 1 757 155 children (average age: 76.3 months), in 1997 stunting reached 8.4%, 4.8% and 3.1% in children with two, one and no Mapuche surnames, respectively. In 2005 it fell to 3.7%, 3.1% and 2.6% - a marked decrease in those with two Mapuche surnames (p0.001). Obesity in 1997 was 11.8%, 12.8% and 13.3%, whilst in 2005 it changed to 17.5, 18.5 and 18.6%, respectively, demonstrating a similar trend to obesity in all groups (p=0.153). Undernutrition was rare (1.1%) and stable. Poverty decreased clearly among the Mapuche population in this period. Conclusion: The marked decrease in stunting in children with a strong indigenous background seems related to a decrease in poverty over the period. Yet, the increase of obesity in all groups deserves further analysis.