The analysis specifically focuses on the most vulnerable groups by measuring “strong undernourishment” (consumption below 80% of the recommended daily amount) and “extreme undernourishment” (below 60%). The study found that one additional day above 110°F during the growing season increases the prevalence of strong caloric undernourishment by 0.36 percentage points, equivalent to impacting an additional 3.1 million people. Notably, the researchers found no effect of heat on less severe measures of diet quality, suggesting that extreme heat primarily exacerbates the nutritional issues of those already struggling with low intake.

Rural households, including dairy producers and subsistence farmers, employ adaptive strategies to combat local crop damage caused by heat. The data shows that after an unusually hot growing season, households reduce the amount of food consumed from home-grown sources while simultaneously increasing their food purchases. Specifically, a day above 110°F leads to a reduction of 4kCal per person per day from home-grown sources, counterbalanced by a 5kCal per person per day increase in purchased food, a pattern consistent across most nutrients studied.

To pay for these increased food purchases, the data suggests that rural workers are shifting their labor allocation. The year following a hot growing season shows fewer people working in agriculture—likely due to decreased need for harvest labor—and a resulting increase in individuals working in the non-agricultural sector. This transition indicates that workers are supplementing their income through alternative employment to afford food grown elsewhere, demonstrating the vital role that accessible labor markets play in mitigating climate shocks.