For 20 years the UK Government has recognised that food advertising plays a part in food choices and hence diets of the population, particularly for children. In 2007 the UK brought in regulations to stop the advertising of less healthy foods on television (TV) during child-specific programming. Less healthy foods were defined using the 2004/2005 nutrient profiling model (NPM) as products high in saturated fat, salt and sugar (HFSS). Evaluations showed that children were still seeing and being affected by the adverts for less healthy foods. To try to mitigate childhood obesity, in 2018, the UK Government announced its intention to consult on further restrictions on the advertising of HFSS products on TV and online. Two years later, the intention to implement a 9pm advertising ban on TV and a further consultation on restricting online advertising of HFSS products was announced. New legislative controls on the advertising of HFSS foods are expected to be brought into legislation in the UK in January 2024. In the present paper, the history of advertising restrictions in the UK and the evidence informing them is reviewed. There will also be a reflection on where further actions might be needed in due course.

Environmental features such as the ‘foodscape’ defined as the physical, sociocultural and economic space in which people encounter meals and foods, might be associated with dietary intake and health outcomes. This review focuses mainly on the spatial approach of the foodscape, i.e. all the local shops, markets, restaurants and sales outlets that provide food supplies in a given area. This review aims to explore the evidence on relationships of urban foodscape with diet and health outcomes and to highlight the limitations in studying these relationships as well as suggestions for future studies. Many systematic reviews on characteristics of the foodscape in relation to weight status outcomes emerged over the last decade and results are equivocal. There is not a direct association between the foodscape and weight status of the individual, rather any association is a distant one. Therefore, it is more appropriate to focus on associations between foodscape and intermediate, more proximal outcomes, such as dietary behaviours. Research on the role of the foodscape in promoting or hindering healthy dietary behaviours are also numerous, and results are again mixed. The diversity of methodologies might partly explain the heterogeneity of these results. Focusing on overall diet quality rather than fruit and vegetable consumption, taking into account multiple characteristics of the foodscape, as well as socioeconomic and contextual differences, might be part of the solution for more consistent results. Consequently, results of such studies could help shape foodscapes, which present a great opportunity for promoting healthier and eventually more sustainable diets.

A Nutrition Society member-led meeting was held online on 18th January 2021 to discuss the role of observational studies in developing public health policy and dietary guidelines. In addition, participants debated media reporting of observational studies and the implications for public perception and trust in science. Speakers outlined the benefits of observational studies and how they fit within the suite of research tools available for estimating dietary intakes and determining their impact on health and disease risk. However, there are clear limitations, such as conscious and unconscious bias, measurement error, confounding and representativeness of populations. Researchers can overcome some of these issues with careful design, awareness of inter-individual variation, open and transparent reporting of findings, and hypothesis-driven statistical analysis to avoid multiple testing errors. Although there is evidence that data provided by nutritional epidemiology can be misleading, strong and thoughtful methodology including pre-registration, risk of bias assessment, awareness of confounders, and evidence grading can minimise potential bias, particularly when conducting systematic reviews. Translation of relative risk into population health impact is important and feeds into the need for responsible lay communication of results via mass media, especially regarding assumptions about cause and effect. Although use of mass media can bring benefits to academia, responsible dissemination is essential and starts with the press release. In conclusion, nutritional epidemiology is an important tool for exploring the risk/benefits of dietary patterns and contributing to health improvement via dietary guidelines, evidence-based policy and responsible lay communication provided its limitations are fully understood.

Dietary patterns (DP) rich in plant foods are associated with improved health and reduced non-communicable disease risk. In October 2021, the Nutrition Society hosted a member-led conference, held online over 2 half days, exploring the latest research findings examining plant-rich DP and health. The aim of the present paper is to summarise the content of the conference and synopses of the individual speaker presentations are included. Topics included epidemiological analysis of plant-rich DP and health outcomes, the effects of dietary interventions which have increased fruit and vegetable (FV) intake on a range of health outcomes, how adherence to plant-rich DP is assessed, the use of biomarkers to assess FV intake and a consideration of how modifying behaviour towards increased FV intake could impact environmental outcomes, planetary health and food systems. In conclusion, although there are still considerable uncertainties which require further research, which were considered as part of the conference and are summarised in this review, adopting a plant-rich DP at a population level could have a considerable impact on diet and health outcomes, as well as planetary health.

Most societies witness an ever increasing prevalence of both obesity and dementia, a scenario related to often underestimated individual and public health burden. Overnutrition and weight gain have been linked with abnormal functionality of homoeostasis brain networks and changes in higher cognitive functions such as reward evaluation, executive functions and learning and memory. In parallel, evidence has accumulated that modifiable factors such as obesity and diet impact the gut–brain axis and modulate brain health and cognition through various pathways. Using neuroimaging data from epidemiological studies and randomised clinical trials, we aim to shed light on the underlying mechanisms and to determine both determinants and consequences of obesity and diet at the level of human brain structure and function. We analysed multimodal 3T MRI of about 2600 randomly selected adults (47 % female, 18–80 years of age, BMI 18–47 kg/m2) of the LIFE-Adult study, a deeply phenotyped population-based cohort. In addition, brain MRI data of controlled intervention studies on weight loss and healthy diets acquired in lean, overweight and obese participants may help to understand the role of the gut–brain axis in food craving and cognitive ageing. We find that higher BMI and visceral fat accumulation correlate with accelerated brain age, microstructure of the hypothalamus, lower thickness and connectivity in default mode- and reward-related areas, as well as with subtle grey matter atrophy and white matter lesion load in non-demented individuals. Mediation analyses indicated that higher visceral fat affects brain tissue through systemic low-grade inflammation, and that obesity-related regional changes translate into cognitive disadvantages. Considering longitudinal studies, some, but not all data indicate beneficial effects of weight loss and healthy diets such as plant-based nutrients and dietary patterns on brain ageing and cognition. Confounding effects of concurrent changes in other lifestyle factors or false positives might help to explain these findings. Therefore a more holistic intervention approach, along with open science tools such as data and code sharing, in-depth pre-registration and pooling of data could help to overcome these limitations. In addition, as higher BMI relates to increased head micro-movements during MRI, and as head motion in turn systematically induces image artefacts, future studies need to rigorously control for head motion during MRI to enable valid neuroimaging results. In sum, our results support the view that overweight and obesity are intertwined with markers of brain health in the general population, and that weight loss and plant-based diets may help to promote brain plasticity. Meta-analyses and longitudinal cohort studies are underway to further differentiate causation from correlation in obesity- and nutrition-brain research.