The global burden of obesity leads to significant morbidity and has major economic implications. In April 2018, Britain will join a growing number of countries attempting to tackle this using fiscal measures when the UK Soft Drinks Industry Levy is introduced. We review recent evidence from natural experiments of the impact of health-related food and drink taxes on consumer behaviour, and discuss the possible consequences of these approaches on purchases and health. We highlight some of the potential indirect consequences and the importance of robust prospective evaluation.

The past half-century has been characterised by major technological developments and massive societal change, which have profoundly changed how food is produced, processed, sold and consumed. These days we are faced with a huge choice of pre-packaged foods when we shop in modern supermarkets and we can buy seasonal food all year round, in and out of season. For decades now, the need to guide choice has been recognised, and retailers and many manufacturers have provided increasing amounts of on-pack information and signposting, and more recently UK retailers have led the way in championing front-of-pack information provision, to supplement the standard back-of-pack nutrient composition table. From a European perspective, the present paper summarises developments in nutrition labelling information and signposting, the legislation that controls on-pack declarations, and research conducted to assess whether or not the information is used, understood and supports healthier choices. It also considers whether more could be done to influence behaviour change positively, giving examples of approaches identified in the research.

The objective of the present paper is to draw lessons from policy development on sustainable diets. It considers the emergence of sustainable diets as a policy issue and reviews the environmental challenge to nutrition science as to what a ‘good’ diet is for contemporary policy. It explores the variations in how sustainable diets have been approached by policy-makers. The paper considers how international United Nations and European Union (EU) policy engagement now centres on the 2015 Sustainable Development Goals and Paris Climate Change Accord, which require changes across food systems. The paper outlines national sustainable diet policy in various countries: Australia, Brazil, France, the Netherlands, Qatar, Sweden, UK and USA. While no overarching common framework for sustainable diets has appeared, a policy typology of lessons for sustainable diets is proposed, differentiating (a) orientation and focus, (b) engagement styles and (c) modes of leadership. The paper considers the particularly tortuous rise and fall of UK governmental interest in sustainable diet advice. Initial engagement in the 2000s turned to disengagement in the 2010s, yet some advice has emerged. The 2016 referendum to leave the EU has created a new period of policy uncertainty for the UK food system. This might marginalise attempts to generate sustainable diet advice, but could also be an opportunity for sustainable diets to be a goal for a sustainable UK food system. The role of nutritionists and other food science professions will be significant in this period of policy flux.

Offering large portions of high-energy-dense (HED) foods increases overall intake in children and adults. This is known as the portion size effect (PSE). It is robust, reliable and enduring. Over time, the PSE may facilitate overeating and ultimately positive energy balance. Therefore, it is important to understand what drives the PSE and what might be done to counter the effects of an environment promoting large portions, especially in children. Explanations for the PSE are many and diverse, ranging from consumer error in estimating portion size to simple heuristics such as cleaning the plate or eating in accordance with consumption norms. However, individual characteristics and hedonic processes influence the PSE, suggesting a more complex explanation than error or heuristics. Here PSE studies are reviewed to identify interventions that can be used to downsize portions of HED foods, with a focus on children who are still learning about social norms for portion size. Although the scientific evidence for the PSE is robust, there is still a need for creative downsizing solutions to facilitate portion control as children and adolescents establish their eating habits.