In
the long term, food systems must heed natural resource limits.
Localized production and dietary changes are often suggested as potential
solutions. However, no U.S. analyses fully evaluate the feasibility
to scale localization across a range of diets. We therefore modeled
the biophysical capacity for regional food systems based on agricultural
land area and productivity, population, and 7 diet scenarios ranging
in meat-intensity, from current consumption to vegan. We estimated
foodshed size, colloquially known as “food miles” for
378 U.S. metropolitan centers, in a hypothetical nationwide closed
system that prioritizes localized food. We found that foodshed size
(weighted average distance traveled) for three land types ranged from
351–428 km (cultivated cropland), 80–492 km (perennial
forage cropland), and 117–799 km (grazing land). Localized
potential varies regionally: foodsheds are generally larger in the
populous Northeast, Southeast, and Southwest than in the Northwest
and the center of the country. However, depending on consumption of
animal-based foods, a sizable proportion of the population could meet
its food needs within 250km: from 35%–53% (cultivated cropland),
39%–94% (perennial forage cropland, 100% for vegan), and 26%–88%
(grazing land, 100% for ovolacto-vegetarian and vegan). All seven
scenarios leave some land unused. This reserve capacity might be used
to supply food to the global market, grow bioenergy crops, or for
conservation.