Global dietary quality, undernutrition and non-communicable disease: a longitudinal modelling study
OBJECTIVES
To determine the relationship between global dietary energy availability and dietary quality, and nutrition-related health outcomes.


DESIGN
A worldwide longitudinal modelling study using country-level data. Data on total dietary energy availability and dietary energy from 10 distinct food groups (as a proxy for dietary quality) were obtained from the FAO Food Balance Sheets database. Indicators of development were abstracted from the World Bank's World Development Indicators database. Data on nutrition and health outcomes were taken from the WHO mortality database and major cross-country analyses. We investigated associations of energy availability from food groups and health and nutrition outcomes in the combined data set using mixed effects models, while adjusting for measures of development.


POPULATION
124 countries over the period 1980-2009.


MAIN OUTCOME MEASURES
Prevalence of stunting in children under 5 years and mortality rate from ischaemic heart disease (IHD) in adults aged 55+ years.


RESULTS
From 1980 to 2009, global dietary energy availability increased, and rates of child stunting and adult IHD mortality declined. After adjustment for measures of development, increased total dietary energy availability was significantly associated with reduced stunting rates (-0.84% per 100 kcal increase in energy, 95% CI -0.97 to -0.72) and non-significantly associated with increased IHD mortality rates (by 4.2 deaths per 100,000/100 kcal increase, 95% CI -1.85 to 10.2). Further analysis demonstrated that the changing availability of energy from food groups (particularly fruit, vegetables, starchy roots, meat, dairy and sugar) was important in explaining the associations with health outcomes.


CONCLUSIONS
Our study has demonstrated that by combining large, publicly available data sets, important patterns underlying trends in diet-related health can be uncovered. These associations remain even after accounting for measures of development over a 30-year period. Further work and joined-up multisectoral thinking will be required to translate these patterns into policies that can improve nutrition and health outcomes globally.