More than 3 million individuals are estimated to be at risk of malnutrition in the UK, of whom about 93% live in the community. BAPEN's Nutrition Screening Week surveys using criteria based on the ‘Malnutrition Universal Screening Tool’ (‘MUST’) revealed that 28% of individuals on admission to hospital and 30–40% of those admitted to care homes in the previous 6 months were malnourished (medium+high risk using ‘MUST’). About three quarters of hospital admissions and about a third of care home admissions came from their own homes with a malnutrition prevalence of 24% in each case. Outpatient studies using ‘MUST’ showed that 16–20% patients were malnourished and these were associated with more hospital admissions and longer length of stay. In sheltered housing, 10–14% of the tenants were found to be malnourished, with an overall estimated absolute prevalence of malnutrition which exceeded that in hospitals. In all cases, the majority of subjects were at high risk of malnutrition. These studies have helped establish the magnitude of the malnutrition problem in the UK and identified the need for integrated strategies between and within care settings. While hospitals provide a good opportunity to identify malnourished patients among more than 10 million patients admitted there annually and the five- to six-fold greater number attending outpatient departments, commissioners and providers of healthcare services should be aware that much of the malnutrition present in the UK originates in the community before admission to hospitals or care homes or attendance at outpatient clinics.