High ambient temperatures effects on the anthropometric status of the population: a systematic review and meta-analysis

Background : The effect of high temperatures and heatwaves on several health outcomes is well known, but there is a knowledge in gap about their effects on nutritional status. This systematic review aims to synthesise research on the association between high temperatures and anthropometric indicators. Methodology : A systematic review and meta-analysis was conducted and the protocol registered in PROSPERO (CRD42024555573). The search included relevant databases and was conducted in October 2024, using terms for “high temperatures”, “heatwaves”, and "anthropometric indicators". Data were extracted and qualitative and quantitative synthesis were performed. Results : Nineteen studies were included, encompassing 3,892,838 participants, predominantly children under the age of 5, mainly from African countries. The studies presented inconsistent results, although most identified inverse relationship between high temperatures and anthropometric indicators. In adults, increased temperatures were associated with elevated risk of both underweight and obesity. In children, the meta-analysis revealed significant reduction of 0.06σ in the Z-score of the Weight-for-Height and 0.02σ in the Z-score of the Height-for-Age indicators for every 1°C increase in average temperature. The observed associations were modest, but with important implications for public health, considering the high proportion of population exposed to the climate changes. Further studies addressing this topic are necessary for a better understanding.