FAO DietSolve: A Diet Optimization Tool for Low- and Middle-Income Countries Developing Dietary Guidelines

Abstract

Background

Low- and middle-income countries (LMICs) developing dietary guidelines often face challenges in translating nutrient requirements into practical, culturally acceptable recommendations due to limited data and technical resources. To address this gap, the Food and Agriculture Organization (FAO) developed FAO DietSolve, a user-friendly tool designed to support such efforts through a systematic and evidence-based approach.

Objective

To present an overview of the FAO DietSolve methodology, demonstrating its application through a hypothetical example, and highlighting its utility in supporting the development of dietary guidelines in LMICs.

Methods

FAO DietSolve uses a mathematical optimization approach using Microsoft Excel's Solver add-in. It combines food groups that meet both nutritional constraints (energy and nutrient requirements) and acceptability constraints (minimum/maximum limits for each food group), while optimizing an objective function. The tool also allows for integration of additional sustainability criteria such as cost, cultural acceptability, and environmental impact into developed dietary patterns. Food groupings are based on representative foods and food consumption data. Objective functions can vary, such as minimizing deviation from observed dietary patterns.

Results

The tool has been utilized by 8 LMICs in developing their national dietary guidelines. The optimized dietary patterns generated have supported the creation of food selection guides tailored to different population groups and informed food graphics.

Conclusions

FAO DietSolve provides LMICs with a practical, data-driven method for developing comprehensive, sustainable, and culturally appropriate dietary patterns. It enables countries to address multiple dimensions of diets and food systems, in line with FAO's new food systems-based dietary guidelines methodology.

Plain language title

FAO DietSolve: A tool for low- and middle-income countries developing dietary guidelines

Plain language summary

Dietary guidelines (also known as food-based dietary guidelines) provide advice to people on how to follow a healthy diet to promote overall health and prevent chronic diseases. Dietary guidelines can also help align public food and nutrition, health and agricultural policies and nutrition education programs that promote health while addressing cultural acceptability, cost and environmental impact. Many low- and middle-income countries (LMICs) struggle to create effective dietary guidelines because they often lack the resources and data needed. This is particularly a problem when nutrient requirements need to be “translated” into recommended dietary patterns, which is often done using an iterative trial-and-error process where experts adjust food group amounts until the nutrient requirements are met. This paper presents a user-friendly tool called FAO DietSolve that was developed to help LMICs do this step in a systematic manner, which saves time and improves objectivity. The paper uses a fictitious example to show how FAO DietSolve works and explain how it fits within the dietary guidelines development process. The tool uses a free function available in Microsoft Excel to combine different food groups to meet specific nutrition requirements while considering cultural preferences and cost. The tool also allows the user to take environmental impact into account when developing the recommended dietary patterns. FAO DietSolve has already been used by 8 LMICs to help develop their national dietary guidelines. It offers a practical and effective way for LMICs that have limited resources and data to develop recommended dietary patterns and food graphics, which are fundamental components of food-based dietary guidelines. It can help countries create recommended dietary patterns that are healthier, more sustainable, and suitable for local populations, addressing not just nutrition but also economic and environmental challenges. FAO DietSolve forms part of FAO's new guidance for countries on how to develop “food systems-based dietary guidelines” using an evidence-informed process involving experts from various disciplines and sectors, considering constraints, opportunities and interconnections throughout the food system.