The theme of The Nutrition Society Spring Conference 2017 was on the interaction between nutrition and exercise for promoting healthy ageing, maintaining cognitive function and improving the metabolic health of the population. The importance of this theme is highlighted by the public health issues surrounding obesity, diabetes and the age-related loss of skeletal muscle mass (sarcopenia). The opening symposium provided a historical perspective of both invasive and non-invasive methodologies for measuring exercise energetics and energy balance. Data derived from these techniques underpin current understanding regarding the metabolic response to nutrition and exercise. Further symposia examined the importance of skeletal muscle for healthy ageing in older men and postmenopausal women. From a nutritional perspective, the potential for animal- v. plant-based protein sources to offset the age-related decline in muscle mass was discussed. The day concluded by discussing the link(s) between nutrition, exercise and brain function. Day 2 commenced with examples of applied equine research illustrating the link between nutrition/exercise and insulin resistance to those of a human model. The final symposium examined the combined role of nutrition and exercise in reducing risk of type 2 diabetes and dyslipidaemia. The overall conclusion from the meeting was that the interaction between diet and physical activity confers greater benefits to human health and performance than either component alone.