Towards The Harmonization Of Healthy Diet Metrics For Global Monitoring

Unhealthy diets are recognized globally as key contributors to morbidity and mortality. As food systems and diets evolve globally, the importance of monitoring what people eat has never been more critical. Yet, there is a lack of consensus on what constitutes healthy diets and how to measure them. In collective recognition of this challenge, the Healthy Diets Monitoring Initiative (HDMI), a partnership among FAO, UNICEF and WHO was established in 2022 with the mission of enabling national and global decision-makers and stakeholders to monitor and achieve healthy diets for people and the planet. We invite all national governments, United Nations agencies and international organizations, implementing partners, donors, civil society organizations, researchers and other key stakeholders (such as those concerned about climate change and food systems) to read our Call to Action and join the Healthy Diets Monitoring Initiative.

With rapidly changing diets, the burden of disease due to the consumption of unhealthy diets is a worldwide concern. Assessment and monitoring of diets across countries and population groups is critical. However, there are no harmonized metrics for tracking how the healthfulness of diets around the world is evolving. Recognizing the need for consensus and action, and to chart a way forward, FAO, UNICEF, and WHO established the Healthy Diets Monitoring Initiative (HDMI) in 2022. The joint mission of this Initiative was articulated through discussions at a technical expert meeting in Bellagio, Italy, in late 2022. This meeting report includes the discussions and conclusions made on the suitability of existing metrics for assessment and monitoring of healthy diets nationally and globally. It also includes a workplan roadmap for the HDMI for the next two years towards the development of a global guidance on healthy diets metrics.

This meeting report is an outcome of the WHO-UNICEF Technical Expert Advisory Group on Nutrition Monitoring (TEAM), which was supported by the Bill & Melinda Gates Foundation. The goal of the consultation was to promote increased communication, coordination and collaboration for the purpose of accelerating progress towards identifying or developing a parsimonious set of metrics for global monitoring of healthy diets for individuals over 2 years of age. Eighty-five participants took part in the consultation, representing a wide range of institutions and roles in the data value chain.

This report scientifically assesses the validity, usefulness, and fitness-for-purpose of existing healthy diet metrics for population assessment for global and national monitoring. Existing healthy diet metrics were identified and critically assessed through a set of criteria for their use as global and national monitoring indicators. After comparative evaluation, three healthy diet metrics were identified as the most suitable for global and national monitoring. The report highlights strengths and weaknesses for the existing healthy diet indicators. Some may be suitable for simple data collection tools and short data collection time while other indicators may require complex quantitative dietary information, lengthy data collection time, and might need to confirm the validity in various contexts. Some of them may only capture a limited number of the sub-constructs of the construct of healthy diets. The report underlines main knowledge gap regarding the population groups for which the metrics could be used – whether these indicators were developed for a particular demographic and/or socioeconomic groups and their ability to be used for other population groups. The report also identifies key priority areas to further explore how these indicators could be used for more population groups and settings.

The National Academies of Sciences, Engineering, and Medicine convened a public workshop in September 2017 to explore the evidence for achieving global harmonization of methodological approaches to establishing nutrient intake recommendations. Participants reviewed current nutrient intake recommendations, discussed the feasibility of harmonizing approaches to setting such recommendations globally, examined the development of principles by which they may be applied in diverse contexts that relate to individuals or populations, or regulatory purposes, and examined perceptions and acceptance of nutrient intake recommendations by different stakeholders. This publication summarizes the presentations and discussions from the workshop.

Recommended intake levels for nutrients and other dietary components were designed initially to prevent nutrient deficiency diseases in a given population, and the original methodological approach used to derive intake values did not include consideration for other applications. However, with the increasing globalization of information and the identification of a variety of factors specific to different population subgroups (e.g., young children and women of reproductive age) that influence their nutritional needs, there has been increasing recognition of the need to consider methodological approaches to deriving nutrient reference values (NRVs) that are applicable across countries and that take into account the varying needs of different population subgroups. There is a need for guidance and recommendations about methodological approaches, as well as their potential for application to an international process for the development of NRVs, and particularly for young children and women of reproductive age. Harmonization of Approaches to Nutrient Reference Values: Applications to Young Children and Women of Reproductive Age examines these issues and makes recommendations for a unified approach to developing NRVs that would be acceptable globally.