The greatest challenge for agriculture is to reduce the trade-offs between productivity and long-term sustainability. Therefore, it is interesting to analyse organic agriculture which is a given set of farm practices that emphasise ecological sustainability. Organic agriculture can be characterised as being less driven by off-farm inputs and being better embedded in ecosystem functions. The literature on public goods and non-commodity outputs of organic farms is overwhelming. Most publications address the positive effects of organic farming on soil fertility, biodiversity maintenance and protection of the natural resources of soil, water and air. As a consequence of focusing on public goods, organic agriculture is less productive. Meta-analyses show that organic agriculture yields range between 0·75 and 0·8 of conventional agriculture. Best practice examples from disadvantaged sites and climate conditions show equal or, in the case of subsistence farming in Sub-Saharan Africa, higher productivity of organic agriculture. Hence, organic agriculture is likely to be a good model for productive and sustainable food production. Underfunding in R&D addressing specific bottlenecks of organic agriculture are the main cause for both crop and livestock yield gaps. Therefore, the potential for improving the performance of organic agriculture through agricultural research is huge. Although organic farming is a niche in most countries, it is at the verge of becoming mainstream in leading European countries. Consumer demand has grown over the past two decades and does not seem to be a limiting factor for the future development of organic agriculture.

This review summarises evidence for an association between vitamin D status and CVD and the mechanisms involved. Vitamin D3 is predominantly provided by the action of UVB from sunlight on skin. Average UK diets supply 2–3 μg/d vitamin D but diets containing at least one portion of oily fish per week supply about 7 μg/d. Pharmacological doses of vitamin D2 (bolus injection of 7500 μg or intakes >50 μg/d) result in a smaller increase in plasma 25(OH)D than those of D3 but physiological doses 5–25 μg/d seem equivalent. Plasma 25(OH)D concentrations are also influenced by clothing, obesity and skin pigmentation. Up to 40 % of the population have plasma 25(OH)D concentrations <25 nmol/l in the winter compared with <10 % in the summer. The relative risk of CVD death is 1·41 (95 % CI 1·18, 1·68) greater in the lowest quintile of plasma 25(OH)D according to meta-analysis of prospective cohort studies. Acute deficiency may inhibit insulin secretion and promote inflammation thus increasing the risk of plaque rupture and arterial thrombosis. Chronic insufficiency may increase arterial stiffness. There is no evidence to support claims of reduced CVD from existing trials with bone-related health outcomes where vitamin D was usually co-administered with calcium. Although several trials with cardiovascular endpoints are in progress, these are using pharmacological doses. In view of the potential toxicity of pharmacological doses, there remains a need for long-term trials of physiological doses of D2 and D3 with CVD incidence as the primary outcome.

The notion of educating the public through generic healthy eating messages has pervaded dietary health promotion efforts over the years and continues to do so through various media, despite little evidence for any enduring impact upon eating behaviour. There is growing evidence, however, that tailored interventions such as those that could be delivered online can be effective in bringing about healthy dietary behaviour change. The present paper brings together evidence from qualitative and quantitative studies that have considered the public perspective of genomics, nutrigenomics and personalised nutrition, including those conducted as part of the EU-funded Food4Me project. Such studies have consistently indicated that although the public hold positive views about nutrigenomics and personalised nutrition, they have reservations about the service providers’ ability to ensure the secure handling of health data. Technological innovation has driven the concept of personalised nutrition forward and now a further technological leap is required to ensure the privacy of online service delivery systems and to protect data gathered in the process of designing personalised nutrition therapies.

Bariatric surgery leads to significant long-term weight loss, particularly Roux-en-Y gastric bypass (RYGB). The mechanisms underlying weight loss have not been fully uncovered. The aim of this review is to explore the changes in food preferences, as a novel mechanism contributing to weight loss, and also focus on the underlying processes modulating eating behaviour after bariatric surgery. Patients after gastric bypass are less hungry and prefer healthier food options. They develop an increased acuity to sweet taste, which is perceived as more intense. The appeal of sweet fatty food decreases, with functional MRI studies showing a corresponding reduction in activation of the brain reward centres to high-energy food cues. Patients experiencing post-ingestive symptoms with sweet and fatty food develop conditioned aversive behaviours towards the triggers. Gut hormones are elevated in RYGB and have the potential to influence the taste system and food hedonics. Current evidence supports a beneficial switch in food preferences after RYGB. Changes within the sensory and reward domain of taste and the development of post-ingestive symptoms appear to be implicated. Gut hormones may be the mediators of these alterations and therefore exploiting this property might prove beneficial for designing future obesity treatment.

Age-related skeletal muscle loss, sarcopenia, cachexia and wider malnutrition (under nutrition) are complex in aetiology with interaction of clinical, social and economic factors. Weight loss and loss of skeletal muscle mass in older people are associated with increased morbidity and mortality with implications for increasing health and social care costs. There is insufficient evidence to identify the ideal treatment options. However, preventing weight loss and loss of skeletal muscle in older age will be keys to reducing morbidity and mortality. This will require all those coming into contact with older people to identify and address weight loss early, including through diet, improving physical activity and increasing social interaction. Public health messages on diet should, in the main, continue to focus on older people achieving current UK dietary recommendations for their age as visually depicted in the eatwell plate together with associated messages regarding dietary supplements where appropriate.

Alterations in the composition and metabolic activity of the gut microbiota appear to contribute to the development of obesity and associated metabolic diseases. However, the extent of this relationship remains unknown. Modulating the gut microbiota with non-digestible carbohydrates (NDC) may exert anti-obesogenic effects through various metabolic pathways including changes to appetite regulation, glucose and lipid metabolism and inflammation. The NDC vary in physicochemical structure and this may govern their physical properties and fermentation by specific gut bacterial populations. Much research in this area has focused on established prebiotics, especially fructans (i.e. inulin and fructo-oligosaccharides); however, there is increasing interest in the metabolic effects of other NDC, such as resistant dextrin. Data presented in this review provide evidence from mechanistic and intervention studies that certain fermentable NDC, including resistant dextrin, are able to modulate the gut microbiota and may alter metabolic process associated with obesity, including appetite regulation, energy and lipid metabolism and inflammation. To confirm these effects and elucidate the responsible mechanisms, further well-controlled human intervention studies are required to investigate the impact of NDC on the composition and function of the gut microbiota and at the same time determine concomitant effects on host metabolism and physiology.

The need to support people to change diet-related behaviour is widely advocated and how to do this effectively in practice is an expanding area of research. Important factors to consider are how healthcare practitioners communicate with their patients and how that communication may affect diet-related behaviour change and subsequent outcomes. The aim of the present paper is to discuss communication skills for behaviour change (CSBC), focusing predominantly on registered dietitians who are required to communicate effectively and have an important role in supporting patients to change diet-related behaviour. The views of dietitians in relation to CSBC have been investigated and respondents have consistently reported that they perceive these skills to be of vital importance in practice. Patient views have reiterated the importance of good CSBC in one-to-one consultations. However, pre-qualification training of dietitians is thought to deliver practitioners who are competent at a minimum level. The need for ongoing continuous professional development (CPD) in relation to CSBC has been recognised but currently most CPD focuses on updating knowledge rather than improving these essential skills. Measuring CSBC in a consistent and objective manner is difficult and an assessment tool, DIET-COMMS, has been developed and validated for this purpose. DIET-COMMS can be used to support CSBC development, but concerns about logistical challenges and acceptability of implementing this in practice have been raised. Although a suitable assessment tool now exists there is a need to develop ways to facilitate assessment of CSBC in practice.