High Altitude Protects Against Early Childhood Obesity: Nationwide Evidence from Colombia

Childhood obesity is an emerging public health challenge globally, with early-life exposures and environmental factors critically shaping long-term metabolic risk. Among these, high-altitude hypoxia has been proposed to influence energy metabolism and adiposity regulation; however, its relationship with early childhood obesity remains insufficiently explored at a population level. This ecological study examined the association between residential altitude and obesity prevalence in children under five years of age across Colombia. Data were obtained from 1,123 municipalities using official national databases: obesity prevalence from the Colombian Institute of Family Welfare (ICBF), population estimates from the National Department of Statistics (DANE), and altitude data from official geographic registries. Municipalities were stratified into four altitude ranges and categorized by population size. We calculated obesity prevalence and odds ratios (OR) to evaluate the risk associated with altitude, adjusting for urbanicity and demographic scale. Among approximately 4.16 million children aged 0-5 years, those residing between 2,000 and 3,000 meters above sea level had significantly lower odds of obesity compared to those living below 1,000 meters (OR: 0.47). This inverse association remained consistent in departmental capital cities and in municipalities stratified by similar population sizes. Notably, higher obesity prevalence in small, low-altitude municipalities suggested potential deficiencies in healthcare access and early prevention. These findings support the hypothesis that altitude may serve as an environmental modulator of early metabolic risk, aligning with the developmental origins of health and disease (DOHaD) framework. Our results call for geographically tailored public health strategies, integrating biological and structural determinants to address early-onset obesity. Further longitudinal and mechanistic studies are warranted to better understand the pathways linking hypoxia, metabolic regulation, and childhood obesity.