Aligning health, environment, and cost aspects of diets: Identifying sustainable dietary patterns in China

Considering the adverse effects of agricultural-food systems on both human health and the environment, this research aimed to identify sustainable diets, which are nutritious, culturally acceptable, affordable, and have low environmental impacts, based on self-reported diets in China. Dietary data was collected with a 3-day 24-h dietary recall and weight food record combined method among 10,324 subjects aged 18–64 year, who participated in the China Health Nutrition Survey 2011. Diet quality was assessed by the Chinese Healthy Eating Index 2016 (CHEI2016). Environmental impact was measured by greenhouse gas emissions (GHGE), total water use (TWU), and land use (LU), and diet costs were calculated using market prices of community surveys. Reduced rank regression derived dietary patterns with 34 food groups as predictor variables, and used CHEI2016 score, dietary greenhouse gas emissions (GHGE), total water use (TWU), land use (LU), and cost of the diet as response variables. Four dietary patterns were identified. Participants with the highest adherence (decile 10) to the "High animal-based food" pattern showed higher dietary GHGE (+57%), TWU (+51%), and LU (+54%) and dietary costs (+64%), compared to the average population's diets. The diet in decile 10 for the "High fruit, low ruminant meat" pattern displayed a 21% higher CHEI2016 score, and higher dietary environmental impact (GHGE +17%; TWU +22%; LU +19%) and dietary costs (+46%) than the average diets. Diets of participants who followed the "High fish, low beverages" pattern showed higher environmental impact (GHGE +39%; TWU +32%; LU +28%) and dietary costs (+19%), but the CHEI2016 score was similar (+0.1%). Finally, the "High wheat, low pork" pattern demonstrated lower environmental impacts (GHGE -17%, TWU -12%, LU -2%) and lower cost of the diet (−2%) but also lower CHEI2016 score (−1%) compared to average population. This study reveals the complex trade-offs between diet quality, environmental sustainability, and dietary costs of current dietary patterns. None of the four patterns achieved the desirable combination of high CHEI2016 scores, reduced environmental impact, and reduced dietary costs. The findings offer insights into sustainable diet choices within the current food system, suggesting dietary guidelines should consider environmental sustainability and cost-effectiveness.