The association between maternal metabolic status at the time of conception and subsequent embryogenesis and offspring development has been studied in detail. However, less attention has been given to the significance of paternal nutrition and metabolism in directing offspring health. Despite this disparity, emerging evidence has begun to highlight an important connection between paternal metabolic well-being, semen quality, embryonic development and ultimately adult offspring health. This has established a new component within the Developmental Origins of Health and Disease hypothesis. Building on the decades of understanding and insight derived from the numerous models of maternal programming, attention is now becoming focused on defining the mechanisms underlying the links between paternal well-being, post-fertilisation development and offspring health. Understanding how the health and fitness of the father impact on semen quality is of fundamental importance for providing better information to intending fathers. Furthermore, assisted reproductive practices such as in vitro fertilisation rely on our ability to select the best quality sperm from a diverse and heterogeneous population. With considerable advances in sequencing capabilities, our understanding of the molecular and epigenetic composition of the sperm and seminal plasma, and their association with male metabolic health, has developed dramatically over recent years. This review will summarise our current understanding of how a father's metabolic status at the time of conception can affect sperm quality, post-fertilisation embryonic and fetal development and offspring health.

With approximately two in three UK adults overweight or obese, one in five living in poverty and our emergence from the Covid-19 pandemic with implications for employment and income status there is an urgent need to understand what it costs to eat healthily and the role that promotions can play in helping householders manage food budgets. The literature suggests that, in affluent countries, price promotions appear to increase consumer food purchases and are applied more frequently to less healthy products than their healthy counterparts. This review discusses the cost of a healthy diet, identifies the prevalence of promotions in both the supermarket setting generally and a typical shopping basket specifically, and discusses the barriers to affording a healthy diet. Given the current policy focus on the cost of living and population health emphasising the need for food shopping to represent health and value for money for better public health outcomes, this review contributes to the evidence base for retailers' and policymakers' consideration as policy solutions are sought to reduce population obesity levels, while ensuring the affordability and accessibility of nutritious food. It is important, given the shift in consumer purchasing behaviour to online shopping as a result of self-isolating or reticence to physically access stores in response to the Covid-19 pandemic, that retail food promotions are available irrespective of the chosen mode of shopping (in-store or online).

Lower household income has been consistently associated with poorer diet quality and poorer dietary health outcomes. Households experiencing poverty find themselves unable to afford enough food, and the food that they can afford is often poor quality, energy dense and low in nutrients. However, the relationship between diet, poverty and health is complex. Not everyone on a low income has a poor diet. Poverty is about more than low incomes and it is not a uniform experience. Particular aspects of the experience of poverty have implications for diet and dietary health. It is increasingly apparent that uncertainty is one of those aspects. Recession, welfare policy, employment trends and widening inequality have created more uncertainty for those on low incomes. In the context of heightened uncertainty, all aspects of household food provisioning – including budgeting, shopping, storage, meal planning and cooking – are more difficult and sometimes impossible. This review will draw on research about food practices and dietary health in low-income neighbourhoods to explore the ways in which experiences of prolonged uncertainty shape dietary practices and impact health and well-being.

The purpose of this article is to describe a series of recent studies from the authors and many of their colleagues aimed at improving the food environments of adolescents in the Netherlands and thereby improving their food choices. These studies are performed in the wider context of national and local strategies for the prevention of overweight and obesity in the Netherlands. Interventions were developed with local stakeholders and carried out in schools, supermarkets and low-income neighbourhoods. We conclude that current national policies in the Netherlands are largely ineffective in reducing the prevalence of overweight and obesity. Local integrated programmes in the Netherlands, however, seem to result in a reduction of overweight, especially in low-income neighbourhoods. It is impossible to say which elements of such an integrated approach are effective elements on their own. We found very little evidence for the effectiveness of separate interventions aimed at small changes in the food environment. This suggests that such interventions are only effective in combination with each other and in a wider systems approach. Future studies are needed to further develop the practical methodology of implementation and evaluation of systems science in combination with participatory action research.

In recent years, a wealth of factors are associated with increased risk of developing non-alcoholic fatty liver disease (NAFLD) and NAFLD is now thought to increase the risk of multiple extra-hepatic diseases. The aim of this review is first to focus on the role of ageing and sex as key, poorly understood risk factors in the development and progression of NAFLD. Secondly, we aim to discuss the roles of white adipose tissue (WAT) and intestinal dysfunction, as producers of extra-hepatic factors known to further contribute to the pathogenesis of NAFLD. Finally, we aim to summarise the role of NAFLD as a multi-system disease affecting other organ systems beyond the liver. Both increased age and male sex increase the risk of NAFLD and this may be partly driven by alterations in the distribution and function of WAT. Similarly, changes in gut microbiota composition and intestinal function with ageing and chronic overnutrition are likely to contribute to the development of NAFLD both directly (i.e. by affecting hepatic function) and indirectly via exacerbating WAT dysfunction. Consequently, the presence of NAFLD significantly increases the risk of various extra-hepatic diseases including CVD, type 2 diabetes mellitus, chronic kidney disease and certain extra-hepatic cancers. Thus changes in WAT and intestinal function with ageing and chronic overnutrition contribute to the development of NAFLD – a multi-system disease that subsequently contributes to the development of other chronic cardiometabolic diseases.

A plant-based diet, which can include small amounts of meat, is the foundation for healthy sustainable diets, which will have co-benefits for health, climate and the environment. Studies show that some of the barriers to making this dietary change and reducing meat consumption are perceptions that plant-based diets are inconvenient, it takes too much time and skills to prepare meals and ingredients are expensive. The food environment is changing and the industry is responding with the exponential increase in the market of highly processed, convenient and cheap plant-based foods. This overcomes some of the barriers, but there is concern about whether they are healthy and environmentally sustainable. Plant-based foods have a halo effect around health and the environment, but many being produced are ultra-processed foods that are high in energy, fat, sugar and salt and have a higher environmental impact than minimally processed plant-based foods. The trend towards eating more highly processed plant-based convenience foods is a concern with regard to both public health and the targets set to reduce greenhouse gas (GHG) emissions. The ‘modern day’ plant-based diet emerging is very different to a more traditional one comprising pulses, vegetables and wholegrain. Studies show that those who are younger and have been a vegetarian for a shorter duration are eating significantly more ultra-processed plant-based foods. While there is a place for convenient, desirable and affordable plant-based food to encourage dietary change, care should be taken that this does not subconsciously set a path which may ultimately be neither healthy nor sustainable.

Obesity is a major burden on the health system in England and the rest of the UK. Obesity prevalence is high in adults and children and most of the UK population are consuming more energy than required, and not meeting other dietary recommendations, including those for saturated fat, free sugars, fibre, oily fish and fruit and vegetables. Over the past 5 years, a number of cross-government policies, both promoting voluntary action and legislative, have been put in place to tackle diet-related health and obesity. The food environment is complex with many influencing factors, some of which act through individual automatic choices. Other factors such as accessibility, advertising, promotion and nudging drive increased food and drink purchases. With continual changes in the food environment favouring fast-food outlets and meal delivery companies alongside the adverse impact of the COVID-19 pandemic on diets and physical activity levels, further governmental action is likely needed to deliver sustained improvements to diet and health.

Implications of the ‘changing world’ for nutrition and nutritionists are considered, using the UK within a global context as an illustration. The first section summarises the slow recognition by policy makers of the significance of the changing world of food and nutrition. The second section ‘Food system stress is now at a critical level’ considers the present scale of global food system stress and the failure so far sufficiently to narrow the gap between evidence and policy change. The year 2021 was earmarked when three major UN conferences had the opportunity to chart food changes ahead. The third section ‘Multi-criteria analysis helps frame 21st century nutrition science’ proposes that multi-criteria analysis is an essential methodology for nutrition within this more complex policy world; nutrition studies can no long exclude social and environmental criteria. The penultimate section ‘Nutrition science can reconnect its life science, social and environmental nutrition traditions to contribute to new paradigm formation’ suggests that nutrition science can now recombine three traditions within its own history to address this complexity: social nutrition, environmental nutrition and life sciences. The final section ‘Priorities ahead’ concludes that this multi-criteria approach to nutrition offers new routes for science and policy influence. Five priorities are identified: (1) clarification of the features of a good food system; (2) new sustainable dietary guidelines which integrate different determinants of sustainability; (3) helping consumer engagement with change; (4) developing improved policy frameworks and (5) contributing to professional channels in these processes. In the UK, while the challenge of narrowing the gap between evidence, policy and change remains daunting, the risks of not attempting to improve the transition to an ecologically sound public health nutrition are even greater.

The concept of plant-based diets has become popular due to the purported benefits for both human health and environmental impact. Although ‘plant-based’ is sometimes used to indicate omnivorous diets with a relatively small component of animal foods, here we take it to mean either vegetarian (plant-based plus dairy products and/or eggs) or vegan (100% plant-based). Important characteristics of plant-based diets which would be expected to be beneficial for long-term health are low intakes of saturated fat and high intakes of dietary fibre, whereas potentially deleterious characteristics are the risk of low intakes of some micronutrients such as vitamin B12, vitamin D, calcium and iodine, particularly in vegans. Vegetarians and vegans typically have lower BMI, serum LDL cholesterol and blood pressure than comparable regular meat-eaters, as well as lower bone mineral density. Vegetarians in the EPIC-Oxford study have a relatively low risk of IHD, diabetes, diverticular disease, kidney stones, cataracts and possibly some cancers, but a relatively high risk of stroke (principally haemorrhagic stroke) and bone fractures, in comparison with meat-eaters. Vegans in EPIC-Oxford have a lower risk of diabetes, diverticular disease and cataracts and a higher risk of fractures, but there are insufficient data for other conditions to draw conclusions. Overall, the health of people following plant-based diets appears to be generally good, with advantages but also some risks, and the extent to which the risks may be mitigated by optimal food choices, fortification and supplementation is not yet known.

The observation that 64% of English adults are overweight or obese despite a rising prevalence in weight-loss attempts suggests our understanding of energy balance is fundamentally flawed. Weight-loss is induced through a negative energy balance; however, we typically view weight change as a static function, in that energy intake and energy expenditure are independent variables, resulting in a fixed rate of weight-loss assuming a constant energy deficit. Such static modelling provides the basis for the clinical assumption that a 14644 kJ (3500 kcal) deficit translates to a 1 lb weight-loss. However, this ‘3500 kcal (14644 kJ) rule’ is consistently shown to significantly overestimate weight-loss. Static modelling disregards obligatory changes in energy expenditure associated with the loss of metabolically active tissue, i.e. skeletal muscle. Additionally, it disregards the presence of adaptive thermogenesis, the underfeeding-associated fall in resting energy expenditure beyond that caused by loss of fat-free mass. This metabolic manipulation of energy expenditure is observed from the onset of energy restriction to maintain weight at a genetically pre-determined set point. As a result, the observed magnitude of weight-loss is disproportionally less, followed by earlier weight plateau, despite strict compliance to a dietary intervention. By simulating dynamic changes in energy expenditure associated with underfeeding, mathematical modelling may provide a more accurate method of weight-loss prediction. However, accuracy at an individual level is limited due to difficulty estimating energy requirements, physical activity and dietary intake in free-living individuals. In the present paper, we aim to outline the contribution of dynamic changes in energy expenditure to weight-loss resistance and weight plateau.