The effectiveness of interventions to improve environmentally sustainable and healthy dietary behaviours among European adults: a systematic review

The current global food system poses risks to the environment and human health. In recent years, there has been vigorous activity in Europe to shift people toward sustainable and healthy dietary behaviours (SHDBs). However, existing research on the effectiveness of interventions to promote SHDBs is scattered and a comprehensive synthesis of the evidence across individual, interpersonal, organisational, community and policy levels is lacking. We conducted a systematic review which aimed to synthesise the evidence from research evaluating the effectiveness of interventions to improve SHDBs among European adults. Interventions included those which aimed to 1. Reduce animal-based food intake or choice, 2. Increase plant-based food intake or choice, 3. Increase the intake or choice of fruit and vegetables, 4. Increase the intake or choice of products with low GHG emissions, 5. Reduce food waste. After a comprehensive literature search, 17 studies met the inclusion criteria. Nine studies were considered at high risk of bias, six at moderate risk, and two at low risk of bias. Multi-level interventions that include individual, organisational and food environment levels in a range of food environment settings are likely to be effective strategies to improve SHDBs. Interventions that identify appropriate intervention points to match each specific food environment context and target population are also likely to promote SHDBs. Future research is needed to evaluate the impact of policy-level SHDBs interventions, which were not represented in this review. There will also need to be high-quality research to evaluate the longer-term effects of SHDBs interventions.