(P03-003-20) Diet Quality and Environmental Sustainability Are Linked, But in Unexpected Ways

Objectives: Studies linking diet quality with environmental impacts in the US have generally not accounted for the additional burden associated with retail losses, inedible portions, and consumer waste. Moreover, there is a need to assess the environmental impacts of shifts in diet quality using data collected directly from individuals, rather than assessing the impacts of nutritionally perfect theoretical diets. This study fills these important research gaps by assessing the relationship between observed diet quality among a nationally-representative sample and the amount of agricultural resources used to produce food.

Methods: Dietary data from 50,014 individuals ≥2 y were collected from the National Health and Nutrition Examination Survey (NHANES, 2005-2016), and diet quality was measured using the Healthy Eating Index-2015 (HEI) and Alternate Healthy Eating Index-2010 (AHEI). Food retail losses, inedible portions, and consumer waste were estimated by linking data from the USDA Loss-adjusted Food Availability data series with dietary data from NHANES. These data were input into the US Foodprint Model, which was modified to estimate the amount of agricultural resources needed to meet food demand.

Results: Daily per capita food demand represented nearly four pounds (1,673 grams) of food, including 7% retail loss, 15% inedible, 24% consumer waste, and 54% consumption. Higher diet quality (HEI and AHEI) was associated with greater retail loss, inedible portions, consumer waste, and consumption (P< 0.001 for all). Higher diet quality was associated (P< 0.05) with lower use of agricultural land (HEI and AHEI), greater use of irrigation water and pesticides (HEI), and lower use of fertilizers (AHEI).

Conclusions: Among a nationally-representative sample of over 50 thousand Americans, higher diet quality was associated with greater food retail loss, inedible portions, consumer waste, and consumption. Higher diet quality was also associated with lower use of some agricultural resources (land and fertilizers), but greater use of others (irrigation water and pesticides). By combining robust measures of diet quality with an advanced food system modeling framework, this study reveals that the link between diet quality and environmental sustainability is more nuanced than previously understood.

Funding Sources: None