Ultra-processed food as a cause of increased energy intake and weight gain? resolving controversy and scientific uncertainty

Ultra-processed foods (UPFs) are industrially formulated food products that contain artificial ingredients and/or additives to preserve shelf life and increase palatability. UPFs have been proposed recently to be a potential causal contributor to ill health and in particular, higher UPF consumption has been suggested to be a major contributor to weight gain and population level obesity. Although there is scientific uncertainty over the causal role UPF consumption has on weight gain and other health outcomes, UPFs have now gained significant public and policy interest. UPFs are already included in some country’s national dietary guidelines and UK government are now considering UPFs in the context of public health policy. In relation to weight gain and obesity, concern over UPFs has been largely informed by cross-sectional observational studies which show an association between higher UPF consumption and heavier body weight. However, it is widely agreed that there is significant scientific uncertainty about why studies show an association between higher UPF consumption and heavier body weight. In particular, it is unclear if level of food processing itself causes people to eat more calories and gain more weight and/or or if it is the less healthy nutritional profile of UPFs (e.g., higher fat, sugar, salt & lower protein and fibre) that explains their association with heavier body weight. Resolving uncertainty surrounding if and how UPFs contribute to obesity will clearly be essential to informing public health policy. In addition, it will also be key to understand how people’s food choices may be affected by dietary guidelines about the health risks of UPFs. Although there is now considerable public and policy interest in UPFs, no research has examined how public facing information about UPFs may affect consumers and whether this is likely to improve or inadvertently worsen the nutritional quality of dietary choices. In this project we will resolve controversy and uncertainty over the potential role that UPFs and food processing have in explaining weight gain & understand how consumers are affected by public facing information on UPFs. In Work Package 1, we will conduct new epidemiological research using longitudinal methods to examine the extent to which UPF consumption prospectively predicts weight gain and the development of obesity across the life course. Importantly, in Work Package 1 we will examine whether the association between UPF consumption and weight gain is explained by the nutritional profile of UPFs or if food processing itself may be responsible. In Work Package 2 we will provide causal evidence on whether UPFs are a contributing factor to higher daily calorie intake and therefore a likely cause of weight gain and obesity. We will conduct a new experiment to identify whether eating UPFs increase a person’s daily calorie intake and whether this is explained by the poorer nutritional profile of UPFs or level of food processing itself. Finally, we will understand the potential impact that public facing information about UPFs has on consumer concern, dietary motives and food choice. We will achieve this in Work Package 3 by conducting a study examining the influence that public facing UPF information has on consumers. During the project we will be guided by stakeholders from government and NGOs. We will actively disseminate findings to the public and policy makers to ensure that project findings can inform ongoing debate about UPFs and public health policy.