Articles
                                        Research in context
                                        Evidence before this study                                             impact of suboptimal intake of each diet component on chronic
                                        We systematically searched MEDLINE and the Global Health               disease mortality and morbidity among 195 countries.
                                        Data Exchange (GHDx) to identify studies providing nationally          Additionally, this study characterises the relationship between
                                        or subnationally representative estimates of consumption of            diet and development and evaluates the trends in the burden of
                                        15 foods and nutrients. We included only studies reporting data        disease attributable to diet from 1990 to 2017. High intake of
                                        collected between Jan 1, 1980, and Dec 31, 2016, in one of the         sodium, low intake of whole grains, and low intake of fruits
                                        195 countries included in this analysis. Studies were                  were the leading dietary risk factors for deaths and DALYs
                                        excluded if done with non-random samples or among specific             globally and in many countries.
                                        subpopulations. We estimated the potential health eﬀects of
                                                                                                               Implications of all the available evidence
                                        each dietary risk by use of the Global Burden of Diseases, Injuries,
                                                                                                               This study highlights the need for improving diet at the global,
                                        and Risk Factors Study comparative risk assessment approach.
                                                                                                               regional, and national level. The findings inform priorities for
                                        Added value of this study                                              population-level interventions to improve diet.
                                        This study provides a comprehensive picture of consumption of
                                        15 dietary factors across nations and quantifies the potential
                                      GBD with respect to dietary risks by comprehensively                     index as the fraction of countries for which we identified
                                      reanalysing all data from 1990 to 2017, using consistent                 any data on the risk factor exposure (table).
                                      methods and definitions.                                                   Our dietary data were from multiple sources and were
                                                                                                               aﬀected by diﬀerent types of biases. We considered 24 h
                                      Methods                                                                  diet recall as the gold standard method for assessing
                                      Selection of dietary risk factors                                        mean intake at the population level and adjusted dietary
                                      We selected 15 dietary risk factors (table) that met GBD                 data from other sources accordingly (appendix). Some
                                      selection criteria for risk factors.10–13 These criteria include         types of dietary data (ie, availability, sales, and household
                                      the importance of the risk factor to either disease burden or            data) were only available for all-age groups and both
                                      policy; the availability of suﬃcient data to estimate risk               sexes. To split these data into standard age-specific and
                                      factor exposure; the strength of the epidemiological                     sex-specific groups, we first estimated the global age and
                                      evidence supporting a causal relationship between risk                   sex patterns of intake using data from nutrition surveys
                                      factor exposure and disease endpoints, and availability of               and then used those patterns to split the availability, sales,
                                      data to quantify the magnitude of this relationship per unit             and household data.
                                      of change in the exposure; and evidence supporting the                     We used the spatiotemporal Gaussian process regression
                                      generalisability of the eﬀects to all populations. The process           method to estimate the mean intake of each dietary risk
                                      of evaluation of the strength of epidemiological evidence                factor by age, sex, country, and year (appendix). To improve
                                      for the causal relationship of each diet–disease pair is                 our estimates in data-sparse models, we tested a wide
          See Online for appendix     described elsewhere10–13 and summarised in the appendix.                 range of covariates with plausible relationships with intake
                                                                                                               and included the covariates with best fit and coeﬃcients in
                                      Dietary intake at the population level                                   the expected direction (appendix).
                                      We did a systematic review of the scientific literature
                                      to identify nationally or subnationally representative                   Eﬀect size of dietary risks on disease endpoints
                                      nutrition surveys providing data on consumption of each                  For each diet–disease pair, we used data from published
   For more on the Global Health      dietary factor (appendix). We also searched the Global                   meta-analyses of prospective observational studies to
 Data Exchange see http://ghdx.       Health Data Exchange website for nationally or sub-                      estimate the relative risk of mortality and morbidity.21 For
                      healthdata.org
                                      nationally representative nutrition surveys and household                diet–disease pairs for which evidence was only available
                                      budget surveys. Additionally, for food groups, we used                   on morbidity, we assumed that the estimated relative
    For more on Euromonitor see
 https://www.euromonitor.com/         national sales data from Euromonitor and national                        risks were also applied to mortality (appendix).
        For more on food balance      availability data from United Nations Food and Agriculture               Considering the relationship of diet and metabolic risk
  sheets see http://www.fao.org/      Organization food balance sheets. For nutrients, we used                 factors and the well established age trend of the relative
             economic/ess/fbs/en/     data on their national availability from the Global Nutrient             risks of metabolic risks for cardiovascular disease and
For the Global Nutrient Database      Database.20 For sodium, we collected data on 24 h urinary                type 2 diabetes, we used the age trend of the relative
 see https://nutrition.healthdata.    sodium, where available. For trans fat, we used sales data               risks of metabolic risk factors22 to estimate the age-
     org/global-nutrient-database
                                      from Euromonitor on hydrogenated vegetable oil. The list                 specific relative risk of dietary risks for cardiovascular
     For the list of all dietary data
          sources see http://ghdx.
                                      of all dietary data sources used in GBD 2017 is publicly                 disease and type 2 diabetes (appendix). To estimate the
  healthdata.org/gbd-2017/data-       available at the Global Health Data Exchange website. For                impact of sodium on outcomes, we first estimated
                       input-sources  each dietary factor, we computed a data representativeness               the relationship between urinary sodium and change
2                                                                                   www.thelancet.com Published online April 3, 2019 http://dx.doi.org/10.1016/S0140-6736(19)30041-8