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Sustainable dietary guidance – such as the universal healthy reference diet proposed by the EAT-Lancet Commission on Food, Planet, Health – is one strategy to improve the health and environmental impacts of dietary choices in the United States (US). The Planetary Health Diet Index (PHDI) is a quantitative measure of adherence to the Commission’s recommendations that to date has not been applied in the US. There is a need to assess PHDI’s relationship with health and environmental indicators and to compare it to heath-focused dietary recommendations already in use, such as the Healthy Eating Index-2015 (HEI-2015) and Dietary Approaches to Stop Hypertension (DASH). Using data from the National Health and Nutrition Examination Survey (NHANES), we examined trends in PHDI adherence and its correlations with fiber, potassium, calcium, and iron. We then compared PHDI to HEI-2015 and DASH in terms of disparities, cardiometabolic indicators (waist circumference, blood pressure, high-density lipoprotein cholesterol, fasting plasma glucose, fasting triglycerides) and dietary greenhouse gas emissions (GHGE). We observed small improvements in PHDI score from 2003-2018 and found positive correlations with dietary fiber and potassium, inverse correlations with dietary calcium, and no impact on dietary iron. In comparing PHDI, HEI-2015, and DASH, disparities by income, education, and race/ethnicity existed for each index. Higher PHDI, HEI-2015, and DASH scores were correlated with improved cardiometabolic indicators and there were few meaningful differences across indices, although PHDI was not correlated with fasting plasma glucose and was the only index correlated with fasting triglycerides. Higher dietary quality on all three indices was associated with lower dietary GHGE. The magnitude of the dietary quality-dietary GHGE relationship was larger for PHDI and DASH than for HEI-2015 and was driven largely by red and processed meat intake. Overall, our results suggest that improved dietary quality in the US has potential benefits for health and emissions, regardless of dietary quality measure used. PHDI and DASH were comparable to HEI-2015 in terms of cardiometabolic indicators and had lower carbon footprints. Incorporating sustainability into US dietary guidelines is a promising strategy to improve diet, health, and environmental outcomes, although continued efforts are needed to promote equity and reduce diet disparities.

Objective: Dietary patterns characterised by high intake of red and processed meat are associated with detrimental health and environmental outcomes. To better understand how Americans consume red and processed meat, this study examined the food groups that are the greatest contributors to red and processed meat intake in US diets. Design: Cross-sectional analysis of total red and processed meat, unprocessed red meat and processed meat using data from the National Health and Nutrition Examination Survey (2015-2016 and 2017-2018). Items containing red or processed meat were classified into thirteen mutually exclusive food groups. For highly consumed food groups (≥10 % of meat intake), contribution to meat intake was further assessed by source, sex, income and education. Setting: Nationally representative sample of the US population. Participants: Teens (aged 12-19 years) and adults (aged ≥20 years) who reported meat consumption (n 8178). Results: Meat mixed dishes (18·6 % (95 % CI 16·2, 20·9)), burgers (17·3 % (95 % CI 15·3, 19·3)) and beef excluding ground (17·0 % (95 % CI 13·8, 20·1)) were the top contributors to unprocessed red meat intake. For processed meat, four food groups made up about four-fifths of total intake: cold cuts and cured meats (37·7 % (95 % CI 34·6, 40·8)), sausages and frankfurters (20·3 % (95 % CI 18·6, 22·0)), bacon (14·0 % (95 % CI 12·3, 15·6)) and pizza (10·1 % (95 % CI 8·7, 11·5)). Fast-food restaurants were the top source for burgers and pizza, whereas stores were the top source for all other highly consumed food groups. Few differences were seen in patterns of intake by sociodemographic characteristics. Conclusions: No single food group accounts for a majority of meat intake in the USA. Many behaviour change opportunities for healthier, more sustainable substitutions exist.