Data categorisation of data extraction points.

Current food production and consumption practices are impacting both human and planetary health. Though these challenges are multifaceted, shifting to healthy dietary choices from sustainable food systems is one solution. Food-based labelling is a common public-health strategy aimed at influencing consumption practices, primarily displaying front-of-pack nutrition labelling to encourage healthier choices. Due to the dual impact of food on human and planetary health there is a growing need to additionally include environmental impact information. However, this potentially conflicting information could overwhelm consumers, necessitating a simplified approach that combines both nutritive and environmental values. Previous work has identified existing models, termed sustainable food profiling models, for labelling of individual food products based on their environmental impacts and nutritive value. Foods are rarely eaten in isolation and are often consumed as composite meals, which aggregate to diets. Therefore, it is important to identify indices that exist to assess or rank meals and diets according to their nutritional and environmental impacts. Following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) 2015 guidelines, our systematic review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on 01 May 2024 (PROSPERO registration ID = CRD42024537149). In the present protocol the methodology to identify and review existing food-based indices for the assessment of nutritive value and environmental impact of meals and diets and their intended public health purpose is described. Our primary research questions are: (i) what food-based indices assessing nutritive value and environmental impact exist for classification or ranking of meals or diets? and (ii) what are the methods used to create, and the key characteristics of, these indices?. The results are expected to increase understanding of, and highlight the variation in, the creation of combined measures for the assessment of nutritive value and environmental impact for meals and diets. Additionally, findings can be used to inform researchers, business, and policy actors on future approaches for labelling foods, meals, or diets in a way that supports healthy and sustainable meal choices and diets.当前食品生产与消费行为正同时对人类健康与地球生态健康造成不利影响。尽管此类挑战具有多面性，但从可持续食品系统（sustainable food systems）转向健康饮食选择，便是破解该困境的可行路径之一。基于食品的标签（food-based labelling）是一种常见的公共卫生策略，旨在引导消费行为，其中尤以包装正面营养标签（front-of-pack nutrition labelling）最为普及，用以鼓励消费者做出更健康的选择。鉴于食品对人类与地球健康的双重影响，在标签中纳入环境影响信息的需求日益迫切。然而，这类可能存在冲突的信息可能会令消费者不堪重负，因此亟需一种兼顾营养与环境价值的简化方案。既往研究已开发出名为可持续食品画像模型（sustainable food profiling models）的现有模型，用于根据单个食品的环境影响与营养价值开展产品标签标注。但人们极少单独食用单一食品，更多情况下是以组合餐食的形式进行消费，最终汇聚为整体膳食。因此，亟需明确可用于根据营养与环境影响对餐食及整体膳食进行评估或排序的相关指标。本研究方案遵循《系统评价与Meta分析方案首选报告条目（PRISMA-P）2015》指南，已于2024年5月1日在国际系统评价前瞻性注册库（PROSPERO）完成注册（注册编号：CRD42024537149）。本方案将详述用于识别、梳理现有食品相关指标的研究方法，此类指标用于评估餐食与膳食的营养价值及环境影响，并明确其既定公共卫生目标。本研究的核心研究问题包括：其一，当前存在哪些可用于对餐食或膳食进行分类或排序、同时评估其营养价值与环境影响的食品相关指标？其二，构建此类指标所采用的方法及其核心特征是什么？研究结果有望增进学界对兼顾营养与环境价值的餐食及膳食评估综合指标构建方式的理解，并揭示该领域的研究差异。此外，本研究发现可为研究者、企业及政策制定者提供参考，助力其未来开发可支持健康与可持续餐食选择及膳食模式的食品、餐食或膳食标签方案。