Understanding the relationship between nutrition and health requires detailed measurements of food and drink habits and the health status of the population at large. Specific research studies may also need to be conducted to test whether certain policy interventions have the desired effect. This evidence can then be used to monitor and develop policies to improve health. Activities include the national collection of information on dietary habits and on the health of the public, often including collecting samples of blood or urine. This may involve liaison with hospitals around the country or using mobile clinics. This requires very rigorous procedures to ensure the data is collected appropriately and handled confidentially and we have developed many new procedures to do so. EWL’s specialist teams analyse information to understand dietary habits and our laboratories are able to measure a very broad range of nutrients in the body. We write reports detailing the results, often for government and these are used to inform the development of public health policy. For example, data from the National Diet and Nutrition Survey is used to identify any deficiencies in specific nutrients, perhaps in particular sub-groups of the population and to monitor changes over time. We are also involved in measuring the response to a micronutrient supplementation in Africa.