The world is waking up to the reality of climate change and the challenge of feeding 10 billion people in a healthy and sustainable way. For population and planetary health, food systems need to change. ‘Food and nutrition: pathways to a sustainable future’ was the first face-to-face Nutrition Society Summer Conference since 2018, bringing together leading contributors from across the globe to explore six pathways to a better tomorrow. Review papers from the conference symposia cut across disciplinary divides showcasing advances in scientific methods and our cumulative understanding of the impact of the food system on climate change. The depth, breadth and advancement of research presented demonstrate the power of collaborative research that can shape industry, individual and population recommendations and create a powerful shift towards the sustainable dietary patterns and systems that are so urgently required.

Most current nutrition policies and dietary recommendations still reflect decades of research addressing the mechanism of action or health risks of individual nutrients. Yet, most high-income countries including the UK are far from reaching the dietary intakes which are recommended for good health. Food-based dietary patterns (DPs) can help target specific combinations of foods that are associated with disease risk, recognising the coexistence of multiple nutrients within foods and their potential synergistic effects. Reduced rank regression (RRR) has emerged as a useful exploratory approach which uses a priori knowledge of the pathway from diet to disease to help identify DPs which are associated with disease risk in a particular population. Here we reviewed the literature with a focus on longitudinal cohort studies using RRR to derive DPs and reporting associations with non-communicable disease risk. We also illustrated the application of the RRR approach using data from the UK Biobank study, where we derived DPs that explained high variability in a set of nutrient response variables. The main DP was characterised by high intakes of chocolate and confectionery, butter and low-fibre bread, and low intakes of fresh fruit and vegetables and showed particularly strong associations with CVD, type 2 diabetes and all-cause mortality, which is consistent with previous studies that derived ‘Western’ or unhealthy DPs. These recent studies conducted in the UK Biobank population together with evidence from previous cohort studies contribute to the emerging evidence base to underpin food-based dietary advice for non-communicable disease prevention.

Gestational diabetes mellitus (GDM) is a global public health problem, and in India, it affects about 20% of pregnancies. India, despite being a tropical country with abundant sunshine has a high prevalence (80%) of vitamin D deficiency (VDD) among reproductive-aged women. Global and Indian evidence links VDD with a higher risk of hyperglycaemia in pregnancy and GDM. VDD has also been implicated in gestational hypertension, preterm birth and poorer offspring health. Global scientific consensus acknowledges the need for maternal vitamin D screening and supplementation, but knowledge gaps exist about optimal blood levels (50–100 nmol/l), and the required vitamin D dosage (400–4000 IU). Diet can provide <10% of the vitamin D requirements, food fortification can deliver limited amounts, and hence optimal antenatal supplementation is key. Prenatal calcium supplements containing 400 IU of vitamin D may be sufficient for calcium absorption and bone health, but may not provide immunomodulatory benefits, including GDM prevention. Increasing evidence calls for higher maternal vitamin D requirements (2000–4000 IU) for skeletal, metabolic and immune health benefits. Current screening and supplementation for maternal VDD in India is low. We need to invest in future studies to determine optimal maternal vitamin D requirements and formulate policies for vitamin D supplementation to prevent GDM. Improving the maternal vitamin D status is an important nutritional priority for policymakers to reduce the large economic burden of non-communicable diseases (10% of India's gross domestic product), and eventually achieve the 2030 UN sustainable development goals.