Background: Increasing Americans' diet quality will require changes to the food supply. Due to the complex nature of the food system, this is not as straightforward as simply increasing the production of healthy foods and decreasing the production of unhealthy foods. Little is known about whether the US food system can produce enough food, given finite agricultural resources, to support shifts toward healthier eating patterns.
Objective: The aim of this study was to model the capacity of the US food system to accommodate a shift toward a healthier diet by 2030.
Methods: A biophysical simulation model estimated the proportion of the US population that could be fed a given diet based on food system constraints, currently and projected to 2030. The model accepted data inputs on food intake, crop yields, and population size. Linear and nonlinear regression models were used to estimate projected food intake and crop yields based on recent historical data (1980-2014). Diet quality was estimated using the Healthy Eating Index-2015.
Results: The US agricultural system can produce enough food to feed 146% of the population by 2030. A greater proportion of the population can be fed a high-quality diet than a low-quality diet (178% compared to 119%). To accommodate increased diet quality, substantial increases in cropland acreage would be needed for fruits (P < 0.001), vegetables (P = 0.002), legumes (P = 0.002), and nuts (P = 0.007); and decreased cropland acreage would be needed for grains (P = 0.002) and sweeteners (P < 0.001).
Conclusions: The US can produce more than enough food to accommodate a shift toward a healthier diet pattern, but even moderate shifts in diet quality would require major transitions in cropland use. The success of this transition is dependent on several factors, like individuals' ease of entry into the agricultural sector, producers' ability to shift production to other crops, and modifications to the food supply chain.
Keywords: Healthy Eating Index-2015; carrying capacity; diet quality; food system; model; sustainability.