There is no branch of medicine in which nutritional considerations do not play some part. Overnutrition, undernutrition or unbalanced nutrition are the major causes of ill health in the world. Conversely, illness causes important nutritional and metabolic problems. The spectrum from lack to excess of nutrients is seamless as a clinical and scientific discipline, the two extremes being linked by the Barker effect by which intrauterine malnutrition and low birth weight predispose to obesity, diabetes and CVD in later life. However, the teaching of nutrition in medical and nursing schools remains sparse. Nutritional care cannot be practised satisfactorily in isolation from other aspects of management, since factors such as drugs, surgery and fluid and electrolyte balance affect nutritional status. Nutritional treatment may also have adverse or beneficial effects according to the composition, amount and mode of delivery of the diet and the clinical context in which it is given. Any benefits of nutritional support may also be negated by shortcomings in other aspects of treatment and must therefore be fully integrated into overall care. One example of this approach is the enhanced recovery after a surgery protocol incorporating immediate pre-operative carbohydrate and early post-operative oral intake with strict attention to zero fluid balance, epidural analgesia and early mobilisation. Other examples include the deleterious effect on surgical outcome of salt and water overload or hyperglycaemia, either of which may negate the benefits of nutritional support. There is a need, therefore, to integrate clinical nutrition more closely, not just into medical and surgical practice, but also into the organisation of health services in the hospital and the community, and into the training of doctors and nurses. Societies originally devoted to parenteral and enteral nutrition need to widen their scope to embrace wider aspects of clinical nutrition.