Environmental effects of sustainability-oriented diet transition in China

Dietary adjustment is widely recognized as an effective way to solve the environment/health predicament, and a more sustainable diet is the final target. The environmental effects of the sustainable oriented diet transition deserve considered, especially given the severe food waste. Here, we explored the links between food supply, food consumption, and food demand of recommended diet from 1990 to 2015 at the individual and national level in China, and then quantified the effects of dietary transition on nitrogen footprints (NF), phosphorus footprints (PF), carbon footprints (CF), and water footprints (WF). Results show that cereal consumption decreased at a rate of 1.6% annually, but it was still higher than the dietary guidelines in 2015. Meat consumption went up and almost 1.5 times the maximum recommended level (Max_RL) in 2015. Milk consumption accounted to 10% of the minimum recommended level (Min_RL). Cereal and meat supplies had exceeded the Max_RL demands by 34% and 47%, respectively. The ratios of food supply to consumption varied from 1.3 for meat to 4.3 for vegetables from 1990 to 2015. For environmental effects, NF, PF, and CF would decrease by 36%,22%, and 29%, but WF increased by 3% when current food consumption in 2015 completely meet with the Min_RL. While NF, PF, CF, and WF would increase by 22%, 63%, 22% and 65% when food supply meet with the food demand of the Max_RL. We would underestimated NF by 4%, but overestimate PF, CF, and WF by 12%, 3%, and 20% if without considering gaps between food supply and consumption. We conclude that ignore the gaps between food supply and consumption would overestimate the environmental impacts when current food consumption transitions to the recommended diet. Measures facilitating the realization of the sustainability-oriented diet rely on dietary patterns adjustment and improving the efficiencies of food supply chain.