Endogenous biological rhythms synchronise human physiology with daily cycles of light-dark, wake-sleep and feeding-fasting. Proper circadian alignment is crucial for physiological function, reflected in the rhythmic expression of molecular clock genes in various tissues, especially in skeletal muscle. Circadian disruption, such as misaligned feeding, dysregulates metabolism and increases the risk of metabolic disorders like type 2 diabetes. Such disturbances are common in critically ill patients, especially those who rely on enteral nutrition. Whilst continuous provision of enteral nutrition is currently the most common practice in critical care, this is largely dictated by convenience rather than evidence. Conversely, some findings indicate that intermittent provision of enteral nutrition aligned with daylight may better support physiological functions and improve clinical/metabolic outcomes. However, there is a critical need for studies of skeletal muscle responses to acutely divergent feeding patterns, in addition to complementary translational research to map tissue-level physiology to whole-body and clinical outcomes.

The workplace is a key environmental determinant of health and well-being. Food choices can be influenced by several workplace-related factors including, but not limited to, working hours, the workplace food environment, job roles and workplace culture. Therefore, the workplace is increasingly viewed as an important place for public health nutrition interventions. However, research in this area is fragmented and heterogeneous due to the wide range of workplace settings and occupational groups. This editorial summarises the research presented at The Nutrition Society Workplace Diet and Health Special Interest Group Satellite Symposium in July 2024 as part of the inaugural Nutrition Society Congress.

The current review will examine the field of food intake biomarkers and the potential use of such biomarkers. Biomarkers of food intake have the potential to be objective measures of intake thus addressing some of the limitations associated with self-reported dietary assessment methods. They are typically food-derived biomarkers present in biological samples and distinct from endogenous metabolites. To date, metabolomic profiling has been successful in identifying several putative food intake biomarkers. With respect to food intake biomarkers, there has been a proliferation of publications in this field. However, caution is needed when interpreting these as food intake biomarkers. Many have not been validated thus hampering their use. While much of the focus to date is on discovery of food intake biomarkers there are excellent examples of how to utilise these biomarkers in nutrition research. Applications include but are not limited to: (1) measurement of adherence to diets in intervention studies (2) objectively predicting intake with no reliance on self-reported data and (3) calibrating self-reported data in large epidemiological studies. Examples of these applications will be covered in this review. While significant progress is achieved to date in the food intake biomarkers field there are a number of key challenges that remain. Examples include lack of databases focused on food-derived metabolites thus hindering the discovery of new biomarkers and the need for new statistical approaches to deal with multiple biomarkers for single foods. Addressing these and other key challenges will be key to development of future opportunities.

A person’s chronotype reflects individual variability in diurnal rhythms for preferred timing of sleep and daily activities such as exercise and food intake. The aim of this review is to provide an overview of the evidence around the influence of chronotype on eating behaviour and appetite control, as well as our perspectives and suggestions for future research. Increasing evidence demonstrates that late chronotype is associated with adverse health outcomes. A late chronotype may exacerbate the influence of greater evening energy intake on overweight/obesity risk and curtail weight management efforts. Furthermore, late chronotypes tend to have worse diet quality, with greater intake of fast foods, caffeine and alcohol and lower intake of fruits and vegetables. Late chronotype is also associated with eating behaviour traits that increase the susceptibility to overconsumption such as disinhibition, food cravings and binge eating. Whether an individual’s chronotype influences appetite in response to food intake and exercise is an area of recent interest that has largely been overlooked. Preliminary evidence suggests additive rather than interactive effects of chronotype and meal timing on appetite and food reward, but that hunger may decrease to a greater extent in response to morning exercise in early chronotypes and in response to evening exercise in late chronotypes. More studies examining the interplay between an individual’s chronotype, food intake/exercise timing and sleep are required as this could be of importance to inform personalised dietary and exercise prescriptions to promote better appetite control and weight management outcomes.

Randomised controlled trials are the ‘gold standard’ approach in nutrition research to show a causal relationship between a dietary intervention and clinically relevant outcomes at the population level. Here we review why different study designs are needed to establish the efficacy of dietary interventions at the individual level and to better account for relevant factors that can also influence the outcomes. Over the past decade, precision nutrition approaches have been developed as a new way to measure the effectiveness of dietary interventions at the individual and population level. Precision nutrition aims to determine the individual factors that are associated with differences in responses to dietary interventions. This is complex, typically needing studies with a large number of participants and using advanced statistical approaches and machine-learning algorithms to identify predictors that can explain why individuals do or do not respond to consuming specific foods, meals or diets, for a given outcome. N-of-1 study designs, which are new to nutrition science, offer a robust alternative approach to assess how an intervention and everyday behaviours affect individual health outcomes. They utilise repeated measures within individuals, rather than baseline and end measures in a larger number of participants, to provide the statistical power required to determine an individual’s responsiveness to an intervention. The adoption of new study designs and modelling approaches, particularly the N-of-1 approach, to examine responses to interventions within individuals, will help to further the understanding of the relationships between diet and health within individuals more effectively and accurately.

Obesity is a chronic, complex and multi-factorial condition with an increasing prevalence worldwide. Irregular eating schedules might be a contributing factor to these numbers through the dysregulation of the circadian system. Time-restricted eating (TRE), an approach that limits eating windows, has been studied as a strategy to treat obesity, aligning eating occasions with metabolic circadian rhythms. This review aims to provide an overview of the impact of TRE protocols on metabolic, inflammatory, oxidative stress and circadian rhythm biomarkers in people with overweight or obesity. Most studies report significant weight loss following TRE protocols. While glucose levels decreased in nearly all TRE interventions, only a few studies demonstrated statistically significant differences when compared to the control groups. The findings for c-reactive protein and TNF-α were inconsistent, with limited significant differences. Changes in lipid profile changes were variable and generally did not reach statistical significance. Both 4-hour and 6-hour TRE interventions significantly reduced 8-isoprostane levels. Additionally, TRE significantly altered clock gene expression, as well as that of genes associated with metabolic regulation in subcutaneous adipose tissue. While the evidence is still inconsistent, limiting eating to a consistent daily window of 8 to 12 h can improve insulin sensitivity, reduce blood glucose, cholesterol and triglyceride levels and promote weight loss. These effects are likely attributable to both direct metabolic impacts and indirect benefits from weight loss and improved dietary habits. However, data on circadian, inflammatory and specific metabolic biomarkers remain scarce and occasionally contradictory, highlighting the need for further research on these interventions.

Systems thinking is deeply rooted in history, as far back as Aristotle. However, it has only relatively recently reemerged as an approach to help us understand and intervene in health and food systems. This is particularly salient, given its impact on environmental and population health. Whilst global food is abundant, many people cannot access affordable, healthy and culturally appropriate food. On the other hand, foods of low nutrient density are widely available. Food systems are complex and require complex thinking and approaches that allow us to consider the influence of multiple factors and how the might system respond to change. In turn, this enables the identification of ‘leverage’ points, where policies or interventions are most likely to have a sustained impact. The Foresight obesity map inspired others to adopt systems approaches to help understand the broader social, economic and environmental determinants of obesity to support intervention/policy development. Evaluation of these requires a consideration of complexity to explore why intervention goals may or may not have been successful and how relationships between components or approaches can be enhanced to support implementation and thereby increase the potential for effectiveness. Overall, approaches to understand, intervene, govern and evaluate food systems must themselves be sufficiently complex, or will ultimately be destroyed by the system it seeks to improve. This review paper aims to introduce readers to the application of systems approaches in research within the context of food systems and health, including its traditional/historical origins.

Sleep is vital for the maintenance of physical and mental health, recovery and performance in athletes. Sleep also has a restorative effect on the immune system and the endocrine system. Sleep must be of adequate duration, timing and quality to promote recovery following training and competition. Inadequate sleep adversely impacts carbohydrate metabolism, appetite, energy intake and protein synthesis affecting recovery from the energy demands of daily living and training/competition related fatigue. Sleep’s role in overall health and well-being has been established. Athletes have high sleep needs and are particularly vulnerable to sleep difficulties due to high training and competition demands, as such the implementation of the potential nutritional interventions to improve sleep duration and quality is commonplace. The use of certain nutrition strategies and supplements has an evidence base i.e. carbohydrate, caffeine, creatine, kiwifruit, magnesium, meal make-up and timing, protein and tart cherry. However, further research involving both foods and supplements is necessary to clarify the interactions between nutrition and the circadian system as there is potential to improve sleep and recovery. Additional research is necessary to clarify guidelines and develop products and protocols for foods and supplements to benefit athlete health, performance and/or recovery. The purpose of this review is to highlight the potential interaction between sleep and nutrition for athletes and how these interactions might benefit sleep and/or recovery.

By involving stakeholders to identify issues, co-design facilitates the creation of solutions aligned with the community’s unique needs and values. However, genuine co-design with consumers across all stages of nutrition intervention research remains uncommon. The aim of this review was to examine notable examples of interventions to improve diets in rural settings that have been co-designed by rural communities. Six studies were identified reporting on community-based and digital interventions to improve diets in rural settings that have been co-designed by rural communities. The level of co-design used varied, with two interventions describing co-design workshops and focus groups over a period of between 6 and 11 months, and others not reporting details on the co-design process. Collectively, most interventions demonstrated positive impacts on dietary markers, including an increase in purchase of fruit and vegetable, an increase in percentage energy from nutrient dense foods and a decrease in intake of high fat meats. While these interventions show promise for improving diets in these under-served communities, it is widely recognised that there is a lack of dietary interventions genuinely co-designed with and for rural communities. Future research should build on these studies to co-design dietary interventions that integrate the benefits of both community-based and digital interventions.

As obesity rates rise globally, addressing modifiable lifestyle factors, such as sleep, presents an opportunity for public health interventions. This review explores the growing evidence linking sleep duration, quality and timing with weight management and dietary behaviours throughout the life course. Observational studies associate short or irregular sleep with increased obesity risk, poor diet quality and metabolic disturbances. Plausible mechanisms include decreased physical activity, heightened hedonic and/or emotional eating, dysregulated appetite signals and circadian misalignment of metabolism, which contribute to a positive energy balance. Unravelling the bidirectional relationship between sleep and weight is challenging; poor sleep exacerbates weight gain, while obesity-related comorbidities such as obstructive sleep apnoea further impair sleep. Despite promising evidence from sleep-restriction studies showing increased energy intake, long-term randomised controlled trials (RCTs) examining interventions designed to improve sleep with weight management as an outcome are lacking. A handful of short-term interventions suggest benefits in reducing energy intake or improving dietary quality, but their effects on weight loss remain inconclusive. This review calls for robust, well-powered RCTs that integrate sleep, diet and physical activity interventions to evaluate the potential of sleep as a core component of obesity prevention and treatment strategies. Currently, there is insufficient evidence to support sleep-focused interventions as a mandatory element in clinical weight-management programmes.

Sustainable diets should promote good health for both the planet and the individual. While there is a clear association between lower environmental impact diets and better health outcomes, intervention studies are needed to determine the range of dietary changes and to understand inter-individual differences in response. Individuals having different responses to dietary interventions are underpinned by a variety of genetic, phenotypic and behavioural factors. The aim of this review is to apply the findings from previous literature examining inter-individual variation and phenotypic response to the future of sustainable healthy diets. Despite changing diets or improving diet quality, physiological responses are varied in randomised controlled trials. To better understand response, individuals can be grouped based on shared baseline characteristics or by their shared response to an intervention. Studies grouping individuals by shared characteristics use a metabolic phenotyping or metabotyping approach which demonstrates that some phenotypes are more predisposed to respond to a particular intervention. Tailoring dietary advice to metabolic phenotype shows promise for improving health and diet quality. However, more evidence is needed to understand the complexity that will come with whole dietary change in the context of sustainable healthy diets. We envisage a future where metabolic phenotyping is an integral element for prescribing personalised nutrition advice for sustainable healthy diets.

The potential influence of the timing of eating on body weight regulation in humans has attracted substantial research interest. This review aims to critically evaluate the evidence on timed eating for weight loss, considering energetic and behavioural components of the timing of eating in humans. It has been hypothesised that timed eating interventions may alter energy balance in favour of weight loss by enhancing energy expenditure, specifically the thermic effect of food. This energetic effect has been suggested to explain greater weight loss which has been observed with certain timed eating interventions, despite comparable self-reported energy intakes to control diets. However, timed eating interventions have little impact on total daily energy expenditure, and the apparent effect of time of day on the thermic effect of food largely represents an artefact of measurement methods that fail to account for underlying circadian variation in RMR. Differences in weight loss observed in free-living interventions are more likely explainable by real differences in energy intake, notwithstanding similar self-reported energy intakes. In addition, the energetic focus tends to overlook the role of behavioural factors influencing the timing of eating, such as appetite regulation chronotype-environment interactions, which may influence energy intake under free-living conditions. Overall, there is scant evidence that timed eating interventions are superior to general energy restriction for weight loss in humans. However, the role of behavioural factors in influencing energy intake may be relevant for adherence to energy-restricted diets, and this aspect remains understudied in human intervention trials.

Current food systems pose risks to both population and environmental health. Reducing the intake of animal-based foods, such as dairy products, and increasing consumption of plant-based foods align with priorities for addressing climate change and promoting overall health. Plant-based alternatives to cow’s milk can be readily substituted for cow’s milk without altering meal patterns and food habits, making them a popular choice among those reducing animal-product consumption. However, plant-based milk alternatives do not necessarily provide the same nutrients as cow’s milk, particularly essential micronutrients like iodine. While national data indicate that the UK is iodine-replete, certain population subgroups (such as pregnant women, women of reproductive age, and vegans) remain at risk of iodine deficiency. Young women are more likely than other age groups to consume plant-based milk alternatives, heightening public health concerns about iodine insufficiency in this demographic. Current consumers of plant-based milk alternatives in the UK have lower iodine intake and status compared to consumers of cow’s milk. Population-level effects of replacing milk with plant-based alternatives vary and depend on factors such as the role of plant-based milk alternatives in the diet (i.e. in addition to, or as a replacement for milk), the presence of other iodine sources in the diet, the consumer’s life stage, and whether the alternatives are fortified with iodine. This review examines the literature on plant-based milk alternatives and iodine intake, focusing on implications of this dietary shift and strategies to improve iodine intake in those opting for plant-based milk alternatives in the UK population.

Chrono-medicine considers circadian biology in disease management, including combined lifestyle and medicine interventions. Exercise and nutritional interventions are well-known for their efficacy in managing type 2 diabetes, and metformin remains a widely used pharmacological agent. However, metformin may reduce exercise capacity and interfere with skeletal muscle adaptations, creating barriers to exercise adherence. Research into optimising the timing of exercise has shown promise, particularly for glycaemic management in people with type 2 diabetes. Aligning exercise timing with circadian rhythms and nutritional intake may maximise benefits. Nutritional timing also plays a crucial role in glycaemic control. Recent research suggests that not only what we eat but when we eat significantly impacts glycaemic control, with strategies like time-restricted feeding (TRF) showing promise in reducing caloric intake, improving glycaemic regulation and enhancing overall metabolic health. These findings suggest that meal timing could be an important adjunct to traditional dietary and exercise approaches in managing diabetes and related metabolic disorders. When taking a holistic view of Diabetes management and the diurnal environment, one must also consider the circadian biology of medicines. Metformin has a circadian profile in plasma, and our recent study suggests that morning exercise combined with pre-breakfast metformin intake reduces glycaemia more effectively than post-breakfast intake. In this review, we aim to explore the integration of circadian biology into type 2 diabetes management by examining the timing of exercise, nutrition and medication. In conclusion, chrono-medicine offers a promising, cost-effective strategy for managing type 2 diabetes. Integrating precision timing of exercise, nutrition and medication into treatment plans requires considering the entire diurnal environment, including lifestyle and occupational factors, to develop comprehensive, evidence-based healthcare strategies.

Psoriasis is a chronic debilitating skin disease affecting 2 % of the UK population. The aetiopathogenesis of psoriasis arises from a combination of genetic susceptibly and lifestyle patterns including stress, infections, alcohol misuse, lack of physical activity and adiposity. This unfavourable gene-lifestyle pairing triggers a series of inflammatory responses resulting in the uncontrolled proliferation of skin cells characteristic of psoriasis, which at present is an incurable disease. Concurrent with the systemic nature of the condition, psoriasis has effects beyond the skin with concomitant cardiometabolic complications, arthritis, gastrointestinal diseases and depression, emphasising the need for other strategies beyond pharmaceutical therapies to support psoriasis treatments. The role of diet in psoriasis management has not been clearly established and only two evidence-based recommendations are available for people with psoriasis. This review aims to critically appraise the research examining dietary patterns in psoriasis populations, highlight the gaps in the evidence-base, and present directions for future research.

Food insecurity (also known as food poverty) is the inability to afford or access a healthy diet. It has become recognised as a public health emergency and is a priority in the context of the environmental, geopolitical and socio-economic implications on businesses, households and civic society. This review paper aims to discuss the merits of collecting food insecurity data and its importance in informing cross-sectoral government and others’ understanding, policymaking and action on hunger. The review paper’s key findings are that concerted action on measuring and mapping food insecurity with the aim of eliminating or reducing its prevalence represents a triple win for government, business and citizens. However, measurement does not provide solutions to food insecurity but contributes importantly to understanding its extent and severity to inform and evaluate proffered solutions. Government, business and food insecurity researchers and commentators cannot merely continue to simply describe food poverty - but must effect meaningful change amidst our communities to improve life quality in a timely way for those experiencing acute and chronic hunger. This is best done by addressing the structural causes of food insecurity through economically, socially and culturally fair and appropriate policy levers, requiring cross-sectoral collaboration. Ultimately, food insecurity requires a long-term, sustainable solution that addresses the policy issues under focus: low income, under/unemployment, rising food prices and Welfare Reform, informed by routine, Government-supported monitoring and reporting of the extent of food poverty among our citizens.

Anaemia affects more than 36 % of all pregnancies globally and is associated with significant maternal and neonatal morbidity and mortality. Iron deficiency is widely recognised as the most common nutritional cause of anaemia but other nutrient deficiencies are also implicated, including the B vitamin riboflavin, albeit its role is largely under-investigated and thus typically overlooked. Riboflavin, in its co-factor forms flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), is required for numerous oxidation-reduction reactions, antioxidant function and in the metabolism of other B vitamins and iron. While clinical deficiency of riboflavin is largely confined to low-income countries, sub-clinical (functional) deficiency is much more widespread, including in high-income countries, and is particularly common among women of reproductive age and during pregnancy. Limited observational evidence from high-income populations suggests that suboptimal riboflavin status contributes to an increased risk of anaemia. Furthermore, randomised controlled trials in pregnant women from low- and middle-income countries have demonstrated beneficial effects of riboflavin on haematological status and anaemia. Various mechanisms have been proposed to explain the contribution of riboflavin deficiency to anaemia, with the strongest evidence pointing to an adverse effect on iron metabolism, given that riboflavin co-factors are required for the release of iron from storage ferritin in the production of red blood cells. Overall, this review investigates riboflavin intakes and status during pregnancy in different populations and evaluates the available evidence for the under-recognised role of riboflavin in the maintenance of haemoglobin concentrations together with its potential to protect against the development of anaemia during pregnancy.

The WHO describes micronutrient deficiencies, or hidden hunger, as a form of malnutrition that occurs due to low intake and/or absorption of minerals and vitamins, putting human development and health at risk. In many cases, emphasis, effort and even policy revolve around the prevention of deficiency of one particular micronutrient in isolation. This is understandable as that micronutrient may be among a group of nutrients of public health concern. Vitamin D is a good exemplar. This review will highlight how the actions taken to tackle low vitamin D status have been highly dependent on the generation of new data and/or new approaches to analysis of existing data, to help develop the evidence-base, inform advice/guidelines, and in some cases, translate into policy. Beyond focus on individual micronutrients, there has also been increasing international attention around hidden hunger, or deficiencies of a range of micronutrients, which can exist unaccompanied by obvious clinical signs but can adversely affect human development and health. A widely quoted estimate of the global prevalence of hidden hunger is a staggering two billion people, but this is now over 30 years old. This review will outline how strategic data sharing and generation is seeking to address this key knowledge gap in relation to the true prevalence of hidden hunger in Europe, a key starting point towards defining sustainable and cost-effective, food-based strategies for its prevention. The availability of data on prevalence and food-based strategies can help inform public policy to eradicate micronutrient deficiency in Europe.

The over consumption of high fat, sugar, and salt foods increases population risk of overweight, obesity and diet-related noncommunicable diseases. The food environment mediates consumer food choices and thus plays an important role in diet quality and related health outcomes. The built food environment, where most people in high-income countries access their food, has been found to be obesogenic. The aim of this review was to investigate the healthfulness of the supermarket food environment. Supermarkets are an important source of healthy foods in the built food environment. However, there are disparities in access to supermarkets, and in several countries, supermarkets located in areas of higher deprivation have an unhealthier consumer food environment. This double burden limits access to healthy foods amongst lower socio-economic groups, contributing to widening disparities in food-related ill health. There is a strong body of evidence supporting improved purchase of healthy foods by increasing the healthfulness of the supermarket consumer food environment. Voluntary measures co-designed with retailers to improve the healthfulness of the supermarket consumer food environment through restriction of product placement and private label reformulation have led to an increase in healthier food purchases. However, evidence also shows that mandatory, structural changes are most effective for improving disparities in the access to healthy food. Future research and policy related to the food environment should consider equitable access to healthy sustainable foods in built and online supermarkets.