This paper uses data from 19 countries to test the link between climate and dietary diversity in children. It finds that higher temperatures are generally associated with lower diet diversity, while higher precipitation is generally associated with greater diet diversity.
The countries considered in the paper are in Asia, West Africa, Southeast Africa, Northern Africa, South America and Central America. The figure below shows average dietary diversity scores across the countries. The scores reflect the number of different food groups consumed in the day before the survey; higher is “better”. Diet diversity was higher in South America and lower in Southeast Africa.
Image: Figure 1, Niles et al. Child individual diet diversity score across 19 countries in the Demographic Health Surveys dataset. Colour gradients indicate the number of food groups eaten by children in the household in the last 24 hours prior to the survey (yellow indicates a higher, i.e. better, score).
The paper then links diet diversity scores to a number of climate, agroecological, socioeconomic and geographic factors, and assesses which of the effects are statistically significant. The figure below shows the size of the effect of each factor. Points to the left of the line indicate a link to lower diet diversity while points to the right are linked to higher diet diversity. Dark circles show statistically significant links; grey dots show statistically insignificant links.
Image: Figure 2, Niles et al. Standardised coefficient effects of different agroecological, geographic, socioeconomic, and climate factors on child diet diversity across 19 countries.
Among the climate factors, the two statistically significant effects are long-term average temperatures, where higher temperatures are linked to lower diet diversity, and precipitation anomalies, where higher precipitation compared to the previous year is linked to greater diet diversity.
The largest effect size is seen for household wealth: diet diversity is much higher for children in the richest households compared to the poorest households.
It is widely anticipated that climate change will negatively affect both food security and diet diversity. Diet diversity is especially critical for children as it correlates with macro and micronutrient intake important for child development. Despite these anticipated links, little empirical evidence has demonstrated a relationship between diet diversity and climate change, especially across large datasets spanning multiple global regions and with more recent climate data. Here we use survey data from 19 countries and more than 107 000 children, coupled with 30 years of precipitation and temperature data, to explore the relationship of climate to child diet diversity while controlling for other agroecological, geographic, and socioeconomic factors. We find that higher long-term temperatures are associated with decreases in overall child diet diversity, while higher rainfall in the previous year, compared to the long-term average rainfall, is associated with greater diet diversity. Examining six regions (Asia, Central America, North Africa, South America, Southeast Africa, and West Africa) individually, we find that five have significant reductions in diet diversity associated with higher temperatures while three have significant increases in diet diversity associated with higher precipitation. In West Africa, increasing rainfall appears to counterbalance the effect of rising temperature impacts on diet diversity. In some regions, the statistical effect of climate on diet diversity is comparable to, or greater than, other common development efforts including those focused on education, improved water and toilets, and poverty reduction. These results suggest that warming temperatures and increasing rainfall variability could have profound short- and long-term impacts on child diet diversity, potentially undermining widespread development interventions aimed at improving food security.
Niles, M.T., Emery, B.F., Wiltshire, S., Brown, M.E., Fisher, B. and Ricketts, T.H., 2020. Climate impacts associated with reduced diet diversity in children across nineteen countries. Environmental Research Letters, 16, 015010.