Improving diet and other lifestyle behaviours has considerable potential for reducing the global burden of non-communicable diseases, promoting better health across the life-course and increasing wellbeing. However, realising this potential will require the development, testing and implementation of much more effective behaviour change interventions than are used conventionally. Evidence-based, personalised (or stratified) interventions which incorporate effective behaviour change techniques (BCT) and which are delivered digitally are likely to be an important route to scalable and sustainable interventions. Progress in developing such interventions will depend on the outcomes of research on: (i) the best bases for personalisation of dietary advice; (ii) identification of BCT which are proven to enhance intervention efficacy; (iii) suitable platforms (digital-based tools) for collection of relevant participant characteristics (e.g. socioeconomic information, current diet and lifestyle and dietary preferences) linked with intelligent systems which use those characteristics to offer tailored feedback and advice in a cost-effective and acceptable manner. Future research should focus on such interventions aiming to reduce health inequalities and to improve overall public health.

The aim of the present paper is to critically review the details of the published nutrition intervention trials, with and without exercise, targeting sarcopenia. Sarcopenia is the loss of muscle mass, strength and/or performance with age. Since amino acids and energy are required for muscle synthesis it is possible that nutritional intake influences sarcopenia. Nutritional studies are challenging to carry out because of the complexity of modulating dietary intake. It is very difficult to change one nutrient without influencing many others, which means that many of the published studies are problematic to interpret. The studies included evaluate whole protein, essential amino acids and β-hydroxyl β-methylbutyrate (HMB). Whole-protein supplementation failed to show a consistent effect on muscle mass, strength or function. This can be explained by the variations in study design, composition of the protein supplement and the failure to monitor voluntary food intake, adherence and baseline nutritional status. Essential amino-acid supplements showed an inconsistent effect but there are only two trials that have significant differences in methodology and the supplement used. The HMB studies are suggestive of a beneficial effect on older adults, but larger well-controlled studies are required that measure outcomes relevant to sarcopenia, ideally in sarcopenic populations. The issues of timing and distribution of protein intake, and increased splanchnic amino-acid sequestration are discussed, and recommendations for future trials are made.

The way that people communicate, consume media and seek and receive information is changing. Forty per cent of the world's population now has an internet connection, the average global social media penetration is 39 % and 1·5 billion people have internet access via mobile phone. This large-scale move in population use of digital, social and mobile media presents an unprecedented opportunity to connect with individuals on issues concerning health. The present paper aims to investigate these opportunities in relation to dietary behaviour change. Several aspects of the digital environment could support behaviour change efforts, including reach, engagement, research, segmentation, accessibility and potential to build credibility, trust, collaboration and advocacy. There are opportunities to influence behaviour online using similar techniques to traditional health promotion programmes; to positively affect health-related knowledge, skills and self-efficacy. The abundance of data on citizens’ digital behaviours, whether through search behaviour, global positioning system tracking, or via demographics and interests captured through social media profiles, offer exciting opportunities for effectively targeting relevant health messages. The digital environment presents great possibilities but also great challenges. Digital communication is uncontrolled, multi-way and co-created and concerns remain in relation to inequalities, privacy, misinformation and lack of evaluation. Although web-based, social-media-based and mobile-based studies tend to show positive results for dietary behaviour change, methodologies have yet to be developed that go beyond basic evaluation criteria and move towards true measures of behaviour change. Novel approaches are necessary both in the digital promotion of behaviour change and in its measurement.

The underlying aetiology of sarcopenia appears multifaceted and not yet fully defined, but ultimately involves the gradual loss of muscle protein content over time. The present evidence suggests that the loss of lean tissue in the elderly is exacerbated by low dietary protein intake. Moreover, acute stable-isotope-based methodologies have demonstrated that the muscle anabolic response to a given amount of protein may decline with age, a phenomenon that has been termed anabolic resistance. Although the mechanism responsible for the inability of muscle to mount a satisfactory anabolic response to protein provision with increasing age is presently unknown, it does not appear due to impaired digestion or absorption of dietary protein. Rather, the issue could reside with any combination of: a diminished delivery of amino acids to peripheral tissues, impaired uptake of amino acids into muscle cells, or an inability of amino acids to elicit intracellular events pivotal for anabolism to occur. Despite the presence of anabolic resistance to dietary protein, present evidence suggests that protein supplementation may be able to overcome these issues, particularly when combined with resistance exercise programmes. As such, protein supplementation may prove to be an effective approach to delay the loss of muscle mass with age and has led to calls for the recommended daily intake of protein to be increased for the elderly population.

Nutrition plays a fundamental role in supporting the structural and functional development of the human brain from conception, throughout early infancy and extending into later life. A growing body of evidence suggests that folate and the metabolically related B-vitamins are essential for brain health across all age groups, owing to their specific roles in C1 metabolism and particularly in the production of S-adenosylmethionine, a universal methyl donor essential for the production of neurotransmitters. Emerging, though not entirely consistent, evidence suggests that maternal folate status throughout pregnancy may influence neurodevelopment and behaviour of the offspring. Furthermore optimal B-vitamin status is associated with better cognitive health in ageing. Of note, a recent clinical trial provided evidence that supplementation with folic acid and related B-vitamins over a 2-year-period reduced global and regional brain atrophy, as measured by MRI scan in older adults. In terms of potential mechanisms, the effects of these B-vitamins on cognitive health may be independent or may be mediated by nutrient–nutrient and/or relevant gene–nutrient interactions. Furthermore, a new area of research suggests that the in utero environment influences health in later life. Folate, an important cofactor in C1 metabolism, is indirectly involved in DNA methylation, which in turn is considered to be one of the epigenetic mechanisms that may underlie fetal programming and brain development. The present review will explore the evidence that supports a role for folate and the related B-vitamins in brain health across the lifecycle, and potential mechanisms to explain such effects.

Carbohydrates provide the major source of energy in the diet and hence the type and amount of carbohydrate consumed is an important consideration for weight control. Recent risk assessments have shown that there is no consistent association between the proportions of energy consumed as carbohydrate and body weight and reinforce the dominance of total energy intake as the primary determinant of body weight. However, they have highlighted evidence that different types of carbohydrate have specific effects on the risk of obesity. Short-term experimental studies suggest that some types of dietary fibre may be linked to increased satiation and cohort studies are supportive of an association between low intakes of fibre-rich, whole-grain foods and weight gain. But these observations are not supported by evidence of effects on body weight in randomised controlled trials, suggesting that high-fibre or whole-grain intake may simply be a marker of a broader dietary pattern. Recent attention has focused on the growing evidence of a positive association between the intake of free sugars and weight gain and particularly the risks linked to consumption of sugar-sweetened beverages (SSB). Given the high population-level intake of free sugars the challenge is to identify actions that will successfully reduce consumption to contribute to reductions in the prevalence of obesity. The present paper considers the range of policy options available, using the Nuffield ladder of intervention to provide a framework for risk management, with a focus on the consumption of SSB. Current policy interventions are largely based around consumer education and encouragement to industry to renovate products to reduce the sugar content of food and drinks and/or reduce portion size, but dietary change has been slow. Further measures, including the use of specific incentives/disincentives may be needed to change consumption patterns, some of which may infringe personal or commercial freedom. For these policies to be implemented will require sustained efforts to create a climate in which such interventions are acceptable or even welcomed by society as an appropriate protection against obesity and other diet-related ill-health.

Nutrition across the lifespan encompasses both preventative and treatment options to maintain health and vitality. This review will focus on the challenge of overconsumption of energy relative to energy expenditure and the consequent development of overweight and obesity, since they are responsible for much of the burden of chronic disease in the developed world. Understanding the mechanisms of hunger and satiety and how particular foodstuffs and nutrients affect appetite and motivation to eat is important for evidence-based interventions to achieve weight control and design of community-wide dietary strategies that reach across the lifespan. Food reformulation for appetite control and weight management requires a knowledge of the mechanisms of hunger and satiety, how food interacts with peripheral and central regulatory systems, and how these interactions change across the lifecourse, allied to the technical capability to generate, evaluate and develop new ingredients and foods with enhanced biological potency based on these mechanisms. Two European Union-funded research projects, Full4Health and SATIN, are adopting these complementary approaches. These research projects straddle the sometimes conflicted ground between justifiable public health concerns on the one hand and the food and drink industry on the other. These multi-disciplinary projects pull together expertise in nutrition, neuroimaging, psychology and food technology that combines with food industry partners to maximise expected impact of the research. Better knowledge of mechanisms regulating hunger/satiety will lead to evidence base for preventive strategies for the European population, to reduction of chronic disease burden and to increased competitiveness of European food industry through the development of new food products.