We developed a physically-based environmental account of US food production systems and integrated these data into the environmental input-output life cycle assessment (EIO-LCA) model. The extended model was used to characterize the food, energy, and water (FEW) intensities of every US economic sector. The model was then applied to every Bureau of Economic Analysis metropolitan statistical area (MSA) to determine their FEW usages.The extended EIO-LCA model can determine the water resource use (kGal), energy resource use (TJ), and food resource use in units of mass (kg) or energy content (kcal) of any economic activity within the United States. We analyzed every economic sector to determine its FEW intensities per dollar of economic output. This data was applied to each of the 382 MSAs to determine their total and per dollar of GDP FEW usages by allocating MSA economic production to the corresponding FEW intensities of US economic sectors. Additionally, a longitudinal study was performed for the Los Angeles-Long Beach-Anaheim, CA, metropolitan statistical area to examine trends from this singular MSA and compare it to the overall results.Results show a strong correlation between GDP and energy use, and between food and water use across MSAs. There is also a correlation between GDP and greenhouse gas emissions. The longitudinal study indicates that these correlations can shift alongside a shifting industrial composition. Comparing MSAs on a per GDP basis reveals that central and southern California tend to be more resource intensive than many other parts of the country, while much of Florida has abnormally low resource requirements.Results of this study enable a more complete understanding of food, energy, and water as key ingredients to a functioning economy. With the addition of the food data to the EIO-LCA framework, researchers will be able to better study the food-energy-water nexus and gain insight into how these three vital resources are interconnected. Applying this extended model to MSAs has demonstrated that all three resources are important to a MSA's vitality, though the exact proportion of each resource may differ across urban areas.© 2017 IOP Publishing Ltd Environ. Res. Lett. 12 (2017) 105003 This urbanization affects sustainable development, as urban residents have higher consumption patterns than their rural counterparts. For instance, in 2011 US urban households spent $7808 (18%) more on consumer expenditures compared to rural households [2]. Urban households also generally use more energy per square foot than rural households [3]. From 2000 to 2010 the US urban population increased by 12.1%, which was higher than the nation's overall growth rate of 9.7% during that same period [4]. Metropolitan areas cannot be sustainable if their consumption of food, energy, and water continues to increase with their growing population.The production and use of FEW are distinctly interconnected. Water is essential for the growing, cleaning, and processing of food. Energy is vital for food production as it pow...

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the interdependence that arises from specialization and trade also leads to a less resilient economy. Unexpected, large economic collapse can arise from a shock to even a single resource, due to each resource's interdependent role in the economy.

Economists rarely model the economy as explicitly bound by earth’s ecological systems. Modeling the dynamic interactions of both human and non-human systems is admittedly a challenging task, as it requires expertise from multiple disciplines. Within the last 10 years, a wide variety of research papers have been published that include some biophysical aspects in a model of the economy. These papers all have one thing in common: the model of the economy includes physical and/or energetic exchanges, as well as monetary exchange. This theme is what defines the emerging sub-discipline of biophysical economics, BPE. BPE models of the economy originate from a variety of disciplines, and thus BPE research articles are published across a wide spectrum of academic journals. As inter-disciplinary researchers ourselves, we want to understand what BPE modeling approaches have been used so far. In this paper, we examine and classify over one hundred published articles that use biophysical models of the economy. Although BPE modeling approaches are quite varied, grouping the research by common characteristics reveals several active research areas. We highlight recent papers that are helpful examples of the most popular BPE modeling strategies. Gaps also exist. Several modeling approaches have not been used in published works yet. We identify which of those gaps could be promising avenues for future research. We conclude by suggesting which BPE modeling approach might be particularly appropriate for a variety of research questions.