BACKGROUND : Major policy agendas are calling for accelerated investment in research that addresses the impact of diet patterns on multiple domains of sustainability.

OBJECTIVE : To evaluate the comparative greenhouse gas emissions, diet cost, and diet quality of plant-based, low grain, restricted carbohydrate, low fat, and time restricted diet patterns on a daily per capita basis.

DESIGN : Dietary data from the National Health and Nutrition Examination Survey (2013-2016, n=4,025) were merged with data on greenhouse gas emissions (GHGE) and food prices from multiple databases. The Healthy Eating Index-2015 was used to measure diet quality.

RESULTS : The plant-based diet pattern had the lowest GHGE (3.5 kg CO2eq, 95% CI: 3.3, 3.8 kg CO2eq) and among the lowest diet cost ($11.51, 95% CI: $10.67, $12.41), but diet quality (45.8, 95% CI: 43.3, 48.5) was similar (P>0.005) to most other diet patterns. All of the sustainability impacts of the low grain diet pattern were intermediate. The restricted carbohydrate diet pattern had the highest diet cost ($18.46, 95% CI: $17.80, $19.13) but intermediate diet quality (46.8, 95% CI: 45.7, 47.9) and moderate-to-high GHGE (5.7 kg CO2eq, 95% CI: 5.4, 5.9 kg CO2eq). The low fat diet pattern had the highest diet quality (52.0, 95% CI: 50.8, 53.1) and intermediate GHGE (4.4 kg CO2eq, 95% CI: 4.1, 4.6 kg CO2eq) and diet cost ($14.53, 95% CI: $13.73, $15.38). The time restricted diet pattern had among the lowest diet quality score (42.6, 95% CI: 40.8, 44.6), had GHGE similar to most other diet patterns (4.6 kg CO2eq, 95% CI: 4.2, 5.0 kg CO2eq), and low-to-moderate diet cost ($12.34, 95% CI: $11.38, $13.40).

CONCLUSIONS : Most diet patterns were associated with sustainability trade-offs. The nature of those trade-offs can help inform discussions on food and nutrition policy in the US, including the National Strategy on Hunger, Nutrition, and Health, and future Dietary Guidelines for Americans.