Kidd Bruce, Mackay Sally, Vandevijvere Stefanie, Swinburn Boyd
Department of Epidemiology and Biostatistics, School of Population Health, The University of Auckland, Auckland, New Zealand.
BMJ Nutr Prev Health. 2021 Jun 9;4(1):275-284. doi: 10.1136/bmjnph-2021-000262. eCollection 2021.
To compare the costs and climate impact (greenhouse gas emissions) associated with current and healthy diets and two healthy and environmentally friendly dietary patterns: flexitarian and vegan.
Modelling study.
Aotearoa (New Zealand).
The distribution of the cost and climate impact (kgCOe/kg of food per fortnight) of 2 weekly current, healthy, vegan and flexitarian household diets was modelled using a list of commonly consumed foods, a set of quantity/serves constraints for each, and constraints for food group and nutrient intakes based on dietary guidelines (Eating and Activity Guidelines for healthy diets and EAT-Lancet reference diet for vegan and flexitarian diets) or nutrition survey data (current diets).
The iterative creation of 210-237 household dietary intakes for each dietary scenario was achieved using computer software adapted for the purpose (DIETCOST). There were stepwise differences between diet scenarios (p<0.001) with the diet having the lowest mean cost in New Zealand Dollars (NZ$584 (95% CI NZ$580 to NZ$588)) per fortnight for a family of four) but highest mean climate impact (597 kgCOe (95% CI 590 to 604 kgCOe)), followed by the healthy diet (NZ$637 (95% CI NZ$632 to NZ$642), 452 kgCOe (95% CI 446 to 458 kgCOe)), the flexitarian diet (NZ$728 (95% CI NZ$723 to NZ$734), 263 kgCOe (95% CI 261 to 265 kgCOe)) and the vegan diet, which had the highest mean cost and lowest mean climate impact (NZ$789, (95% CI NZ$784 to NZ$794), 203 kgCOe (95% CI 201 to 204 kgCOe)). There was a negative relationship between cost and climate impact across diets and a positive relationship within diets.
Moving from current diets towards sustainable healthy diets (SHDs) will reduce climate impact but generally at a higher cost to households. The results reflect trade-offs, with the larger constraints placed on diets, the greater cost and factors such as nutritional adequacy, variety, cost and low-emissions foods being considered. Further monitoring and policies are needed to support population transitions that are country specific from current diets to SHD.
比较当前饮食、健康饮食以及两种健康且环保的饮食模式（弹性素食和纯素食）的成本及气候影响（温室气体排放）。
建模研究。
奥特亚罗瓦（新西兰）。
使用常见食物清单、每种食物的一组数量/份数限制以及基于饮食指南（健康饮食的饮食与活动指南以及纯素食和弹性素食饮食的EAT-柳叶刀参考饮食）或营养调查数据（当前饮食）的食物类别和营养素摄入限制，对每两周一次的当前、健康、纯素食和弹性素食家庭饮食的成本及气候影响（每两周每千克食物的千克二氧化碳当量）分布进行建模。
使用为此目的改编的计算机软件（DIETCOST），为每种饮食方案迭代创建了210 - 237种家庭饮食摄入量。饮食方案之间存在逐步差异（p<0.001），对于一个四口之家，新西兰元（NZ$）成本最低的饮食（每两周584新西兰元（95%置信区间为580至588新西兰元））但气候影响均值最高（597千克二氧化碳当量（95%置信区间为590至604千克二氧化碳当量）），其次是健康饮食（637新西兰元（95%置信区间为632至642新西兰元），452千克二氧化碳当量（95%置信区间为446至458千克二氧化碳当量））、弹性素食饮食（728新西兰元（95%置信区间为723至734新西兰元），263千克二氧化碳当量（95%置信区间为261至265千克二氧化碳当量））和纯素食饮食，其成本均值最高且气候影响均值最低（789新西兰元，（95%置信区间为784至794新西兰元），203千克二氧化碳当量（95%置信区间为201至204千克二氧化碳当量））。不同饮食的成本与气候影响之间呈负相关，同一饮食内成本与气候影响呈正相关。
从当前饮食转向可持续健康饮食（SHD）将减少气候影响，但通常家庭成本更高。结果反映了权衡取舍，饮食限制越大，成本越高，同时还考虑了营养充足性、多样性、成本和低排放食物等因素。需要进一步监测和制定政策，以支持针对特定国家从当前饮食向可持续健康饮食的人群转变。
