Use of the DELTA Model to Understand the Food System and Global Nutrition

Abstract

Background Increasing attention is being directed at the environmental, social, and economic sustainability of the global food system. However, a key aspect of a sustainable food system should be its ability to deliver nutrition to the global population. Quantifying nutrient adequacy with current tools is challenging. Objective To produce a computational model illustrating the nutrient adequacy of current and proposed global food systems. Methods The DELTA Model was constructed using global food commodity balance sheet data, alongside demographic and nutrient requirement data from UN and European Food Safety Authority sources. It also includes nutrient bioavailability considerations for protein, the indispensable amino acids, iron, and zinc, sourced from scientific literature. Results The DELTA Model calculates global per capita nutrient availability under conditions of equal distribution and identifies areas of nutrient deficiency for various food system scenarios. Modeling the 2018 global food system showed that it supplied insufficient calcium (64% of demographically weighted target intake) and vitamin E (69%), despite supplying sufficient macronutrients. Several future scenarios were modeled, including variations in waste; scaling up current food production for the 2030 global population; plant-based food production systems; and removing sugar crops from the global food system. Each of these scenarios fell short of meeting requirements for multiple nutrients. These results emphasize the need for a balanced approach in the design of future food systems. Conclusions Nutrient adequacy must be at the forefront of the sustainable food system debate. The DELTA Model was designed for both experts and nonexperts to inform this debate as to what may be possible, practical, and optimal for our food system. The model results strongly suggest that both plant and animal foods are necessary to achieve global nutrition. The model is freely available for public use so that anyone can explore current and simulated global food systems.

Animal and plant-sourced nutrition: complementary not competitive

“…While the degree of reduction of animal-sourced food production and consumption varies in these recom mendations, they share this common theme. However, animal-sourced foods are well known as nutrient dense relative to energy content and play a major role in the nutrition of billions of people (Murphy and Allen 2003;Adesogan et al 2020;Smith et al 2021). Given the challenges of delivering nutrition to a growing number of people, how should the production of food change in the future to ensure adequate global nutrition, and what role do plant-and animal-sourced foods play?…”

Modeling the Contribution of Meat to Global Nutrient Availability

“…A previous publication on the DELTA Model has shown the challenge in meeting global nutrient requirements in the absence of meat (15). Vitamin B12 is a particularly strong example of this, given that more than half of 2018 availability in food was sourced from meat, and total availability only slightly exceeded global requirement (15,16).…”

“…A previous publication on the DELTA Model has shown the challenge in meeting global nutrient requirements in the absence of meat (15). Vitamin B12 is a particularly strong example of this, given that more than half of 2018 availability in food was sourced from meat, and total availability only slightly exceeded global requirement (15,16). Thus, in a no meat scenario for 2030, with all other food production increased by 20%, the DELTA Model predicted a vitamin B12 gap of 35%, alongside gaps for several other nutrients (15).…”

“…The results detailed here were obtained from use of the DELTA Model (version 1.3) (15,16). This model is available online and was developed by the authors as part of the Sustainable Nutrition Initiative.…”

“…This model is available online and was developed by the authors as part of the Sustainable Nutrition Initiative. 1 An overview of the model is given here; a full description can be found in Smith et al (15).…”