Debate persists around the food production and dietary changes needed to improve sustainability of our global food system. We reviewed 29 studies in high‐income countries that used various methodologies to define a healthier, more sustainable diet. Diets aligned with dietary guidelines, containing less meat and higher amounts of plant‐derived foods (vegetables, pulses [beans/lentils], fruit, wholegrains, nuts, seeds) would likely offer environmental benefits (~20–50% lower greenhouse gas emissions [GHGE] and land use) and improve population health, although may not reduce water footprint. Changes in consumption of milk products and eggs were inconsistent in optimisation studies, perhaps reflecting trade‐offs between their nutrient contribution and environmental impact. Foods high in fat, salt and/or sugar, and beverages (e.g. tea, coffee and fruit juices) contributed substantially to environmental footprints in some studies. Vegetarian and vegan diets may deliver larger environmental benefits, but are unlikely to be widely adopted, and may reduce intakes and/or bioavailability of some essential nutrients (e.g. iron, zinc, iodine and B12). We recommend adherence to existing government dietary guidelines as a more realistic goal to improve environmental (e.g. 30% lower GHGE in the UK) and health impacts of diets, recognising that adherence is currently relatively poor. Wider considerations include: context‐specific nutritional, health, cost and cultural needs; need for public engagement to understand barriers/motivators; better understanding of the wider implications and trade‐offs linked to dietary and food system changes and how these can be managed, so that benefits in high‐income countries do not come at the expense of greater ‘outsourced’ environmental impacts in other regions.

Interesterification rearranges the position of fatty acids within triacylglycerols, the main component of dietary fat, altering physical properties such as the melting point and providing suitable functionality for use in a range of food applications. Interesterified (IE) fats are one of a number of alternatives which have been adopted to reformulate products to remove fats containing trans fatty acids generated during partial hydrogenation, which are known to be detrimental to cardiovascular health. The use of IE fats can also reduce the saturated fatty acid (SFA) content of the final product (e.g. up to 20% in spreads), while maintaining suitable physical properties (e.g. melt profile). A novel analysis was presented during the roundtable which combined data from the UK National Diet and Nutrition Survey (2012/2013–2013/2014) with expert industry knowledge of the IE fats typically used in food products, to provide the first known estimate of population intakes of IE fats among UK children and adults. IE fats were found to contribute approximately 1% of daily energy across all ages. The major contributors to overall IE fat intakes were fat spreads (~54%) and bakery products (~22%), as well as biscuits (~8%), dairy cream alternatives (~6%) and confectionery (~6%). Increasing use of IE fats could contribute towards reducing total SFA intakes in the population, but would depend on which food products were reformulated and their frequency of consumption among sub‐groups of the population. Studies comparing the effect of IE and non‐IE fats on markers of lipid metabolism have not shown any consistent differences, either in the fasted or in the postprandial state, suggesting a neutral effect of IE fats on cardiovascular disease risk. However, these studies did not use the type of IE fats present in the food supply. This issue has been addressed in two studies by King's College London, which measured the postprandial response to a commercially relevant palm stearin/palm kernel (80:20) IE ‘hard stock’, although again no consistent effects of the IE fat on markers of lipid metabolism were found. Another study is currently investigating the same IE hard stock, consumed as a fat spread (blended with vegetable oil), and will measure a broader range of postprandial cardiometabolic risk factors. However, further long‐term trials using commercially relevant IE fats are needed. Subsequent to the roundtable, a consumer survey of UK adults (n = 2062; aged 18+ years) suggested that there is confusion about the health effects of dietary fats/fatty acids, including trans fats and partially hydrogenated fats. This may indicate that providing evidence‐based information to the public on dietary fats and health could be helpful, including the reformulation efforts of food producers and retailers to improve the fatty acid profile of some commonly consumed foods.

A multi-disciplinary expert group met to discuss vitamin D deficiency in the UK and strategies for improving population intakes and status. Changes to UK Government advice since the 1st Rank Forum on Vitamin D (2009) were discussed, including rationale for setting a reference nutrient intake (10 µg/d; 400 IU/d) for adults and children (4+ years). Current UK data show inadequate intakes among all age groups and high prevalence of low vitamin D status among specific groups (e.g. pregnant women and adolescent males/females). Evidence of widespread deficiency within some minority ethnic groups, resulting in nutritional rickets (particularly among Black and South Asian infants), raised particular concern. Latest data indicate that UK population vitamin D intakes and status reamain relatively unchanged since Government recommendations changed in 2016. Vitamin D food fortification was discussed as a potential strategy to increase population intakes. Data from dose–response and dietary modelling studies indicate dairy products, bread, hens’ eggs and some meats as potential fortification vehicles. Vitamin D₃appears more effective than vitamin D₂for raising serum 25-hydroxyvitamin D concentration, which has implications for choice of fortificant. Other considerations for successful fortification strategies include: (i) need for ‘real-world’ cost information for use in modelling work; (ii) supportive food legislation; (iii) improved consumer and health professional understanding of vitamin D’s importance; (iv) clinical consequences of inadequate vitamin D status and (v) consistent communication of Government advice across health/social care professions, and via the food industry. These areas urgently require further research to enable universal improvement in vitamin D intakes and status in the UK population.

Dietary fructose has been linked to an increased post-prandial triglyceride (TG) level; which is an established independent risk factor for cardiovascular disease. Although much research has focused on the effects of fructose consumption on liver-derived very-low density lipoprotein (VLDL); emerging evidence also suggests that fructose may raise post-prandial TG levels by affecting the metabolism of enterocytes of the small intestine. Enterocytes have become well recognised for their ability to transiently store lipids following a meal and to thus control post-prandial TG levels according to the rate of chylomicron (CM) lipoprotein synthesis and secretion. The influence of fructose consumption on several aspects of enterocyte lipid metabolism are discussed; including de novo lipogenesis; apolipoprotein B48 and CM-TG production; based on the findings of animal and human isotopic tracer studies. Methodological issues affecting the interpretation of fructose studies conducted to date are highlighted; including the accurate separation of CM and VLDL. Although the available evidence to date is limited; disruption of enterocyte lipid metabolism may make a meaningful contribution to the hypertriglyceridaemia often associated with fructose consumption.