Table 1.

Approaches used to consider the health aspect in research on environmentally sustainable diets

Approach	Question addressed by the approach	Considerations for selection
A. Simple approaches
Food item replacement	What would be the change in environmental sustainability when replacing a particular food item or food group in the diet by a more sustainable alternative food item or food group?	∙Omits dietary composition and micronutrient intake ∙Focuses on sustainability and therefore lacks the consumer’s perspective to develop acceptable diets
B. Approaches capturing the complexity of the diet
B1. Dietary guidelines	What would be the change in environmental sustainability when dietary guidelines are met?	∙The recommended diet is considered as the optimised diet for nutritional health, and not necessarily for environmental sustainability ∙Not yet a consensus on what a healthy diet includes, resulting in a variety of dietary recommendations and thus recommended diets
B2. Dietary quality scores	How is dietary quality – as assessed by a score – related to environmental sustainability?	∙One overall score reflects dietary intake as a whole; however, there are score-related limitations ∙A need for detailed nutritional data to calculate the score ∙Focus on nutritional health
B3. Diet modelling techniques	What would be the food composition of a diet when aiming at the optimisation of multiple diet-related factors (e.g. health, environmental sustainability, acceptability, affordability, accessibility, etc.)?	∙Possibly, the designed diet is still a sub-optimised diet as it is driven by acceptability constraints and the data availability ∙Outcome of the optimised diet is presented as a list of food items in a specified quantity; hence the need for translation into dietary guidelines that can be communicated in a coherent way to the public
C. Approaches evaluating the diet-related health impact
Diet-related health impact analysis	What would be the change in health impact based on nutrient adequacy and/or health/disease outcome when individuals adopt a diet that is more environmentally sustainable?	∙Health impact analyses are usually based on published meta-analyses by modelling counterfactual diets ∙Nutrient adequacy and diet-related health/disease outcomes are predictive for the future of dietary change