Differences in modelled estimates of global dietary intake

Abstract

Robust global dietary data are essential for understanding the risk of undernutrition, obesity, and diet-related non-communicable diseases, which contribute substantially to the global burden of disease.1GBD 2019 Risk Factors CollaboratorsGlobal burden of 87 risk factors in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019.Lancet. 2020; 396: 1223-1249Summary Full Text Full Text PDF PubMed Scopus (266) Google Scholar Two separate entities—the Global Dietary Database (GDD) and the Global Burden of Disease (GBD) 2017 Diet Collaborators2Afshin A Sur PJ Fay KA et al.Health effects of dietary risks in 195 countries, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017.Lancet. 2019; 393: 1958-1972Summary Full Text Full Text PDF PubMed Scopus (984) Google Scholar—have compiled global dietary and proxy data to model quantitative intakes for adults from nearly every country. The underlying data in the modelled estimates from GDD include 24-h recalls, food frequency and Demographic and Health Survey questionnaires, biomarkers, and household surveys. GBD-modelled estimates are primarily based on food availability data from the Food and Agriculture Organization Supply Utilization Accounts and food sales data from Euromonitor, but also on dietary recalls, food frequency questionnaires, and household budget surveys. The most recent GDD estimates are for 2015 for adults aged 20 years and older, while the closest corresponding GBD estimates are for 2017 for adults aged 25 years and older. We compared GDD 2015 and GBD 2017 estimates for four food groups—fruits, nuts and seeds, unprocessed red meat, and sugar-sweetened beverages—and found considerable differences for many countries (appendix). The magnitude of many of the differences far exceed any reasonable attribution to slightly differing years and age groups between the two estimates. The use of GDD or GBD estimates could suggest vastly different conclusions about diet quality, nutrient adequacy, and risk of non-communicable diseases, if these estimates were used, for example, to establish to what extent populations are following dietary guidelines. The differences in these estimates reveal that evidence on dietary intake is currently insufficient to produce robust, reliable, and replicable estimates of quantitative intake across countries globally. These estimates cannot substitute for high-quality dietary intake data. More dietary intake data from representative populations are needed, particularly for low-income and middle-income countries. Modelling efforts must ensure full transparency of data sources and methods used, including metadata and modelled estimates. The current focus on diet quality is unprecedented, but the existence of two separate efforts to model global dietary data with often very different results is problematic. The approaches urgently need to be harmonised, particularly the underlying databases, and have standardised methods for classifying food groups such as sugar-sweetened beverages.3Merkel PE Ditto EK Robien K Sylvetsky AC Chaos in a bottle—a critical evaluation of beverage categorization in nutrition research.Adv Nutr. 2020; 11: 1414-1428Crossref PubMed Scopus (2) Google Scholar We greatly appreciate the efforts to collate data and model dietary intakes but caution use of these estimates until the approaches are harmonised and validated across various settings globally. The GDD 2015 estimates are designated as beta estimates, not intended for publication but publicly available online. The GBD 2017 diet estimates are available online on the Food Systems Dashboard. TB and LMN are employees of the Global Alliance for Improved Nutrition, through which they have received grants for the Food Systems Dashboard, which displays global dietary data, and the Global Diet Quality Project, which collects and analyses diet quality data globally through the Gallup World Poll. AH has received personal fees for the Food Systems Dashboard and has received grants for the Global Diet Quality Project. SS is an employee of the Bill & Melinda Gates Foundation, which also provides grants to the two projects. SYH declares no competing interests. Download .pdf (.3 MB) Help with pdf files Supplementary appendix Global burden of 87 risk factors in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019Overall, the record for reducing exposure to harmful risks over the past three decades is poor. Success with reducing smoking and lead exposure through regulatory policy might point the way for a stronger role for public policy on other risks in addition to continued efforts to provide information on risk factor harm to the general public. Full-Text PDF Open Access