Promoting Healthy and Sustainable Diets: Evaluating Interventions

This project aims to analyse the wide range of approaches taken to encourage healthy and environmentally sustainable diets.

Global dietary trends are on an unsustainable path. The incidence of obesity is increasing in developed and developing countries alike, along with the burden of diet-related non-communicable diseases (NCDs). The food system’s environmental footprint is growing. Agriculture accounts for about 70 per cent of water use and is a principal driver of deforestation. The emissions associated with meat and dairy production are estimated to account for 14.5 per cent of the global total: more than direct emissions from global transport. 

Demand-side responses to these issues vary according to the level of government intervention, ranging from regulatory approaches to eliminate or restrict the availability of certain foods or ingredients to designing choice architecture to influence or ‘nudge’ consumer choices towards desirable outcomes.  

While interventions to restrict choice through banning, capping or taxing ingredients such as alcohol, sugar and fats are part of government-led approaches, many interventions fall into what might be considered ‘self-regulation’ ( business is seen to act voluntarily). Some forms of ‘self-regulation’ involve governments and business working together, often with the threat of regulation providing the incentive. 

More widely, many food producers are responding to the WHO’s plans to tackle obesity and related NCDs with self-regulation and the production of ‘healthier’ foods. Other forms of ‘self-regulation’ may not involve governments at all, such as many sustainability labelling schemes. Some of these may not even involve independent third parties to ‘verify’ compliance – effectively allowing companies to self-certify. 

There is a wide range of approaches being taken in different countries in pursuit of different environmental and health objectives. Uncertainty surrounds the efficacy and unintended consequences of many interventions. Factors that need to be considered when judging their efficacy include how interventions are designed, the context in which they are implemented, the challenge of isolating causality and the timescale over which efficacy is judged.

There is a need for independent research to review the experience to date of different approaches in demand-side health and environmental interventions, identify lessons learned, barriers and gaps in knowledge.


Research staff from Chatham House and the Food Climate Research Network (Environmental Change Institute, University of Oxford) undertook a literature review to assess the evidence on the efficacy and unintended consequences of different demand-side interventions for health or environmental objectives. This was complemented by an expert workshop at Chatham House with international experts to discuss the results of the research and identify recommendations for decision-makers.  


This project is funded by the EAT Forum.