What is nutritional surveillance?

Surveillance as a process for assessing the nation’s health has become steadily more sophisticated as the emphasis has moved from considering only mortality rates to analysing key risk factors and morbidity trends. The data being collected are complex and massive with the variety of sources presenting problems in collation; this needs to be rapid to allow early and effective responses. Nutritional surveillance is now changing in the UK from a concentration on child growth to the use of new measures for assessing chronic diseases. The continued collection of classic information on mortality trends and their linking to additional data, e.g. on fetal and infantile growth, remains important for developing major new hypotheses on the relationship between diet and health. The UK has an opportunity, with its newly developing nutritional surveillance scheme, of forming a focus for a new and integrated European scheme which could prove invaluable in the decades to come. The unsuspecting nutritionist may be forgiven for viewing the issue of surveillance as boring since it conjures up images of endless analyses of routinely collected statistics emanating from agencies with little interest in the intricacies of diet, metabolism or the molecular complexities which so delight the nutritional scientist. But we continue to be surprised by the value of surveillance in revealing gaps in our understanding. For example, our latest interest in nutrient-gene interaction comes from this field (the idea that changes in nutrition in utero or during the first few months of life may lead to the selective growth of specific clones of cells or to permanently imprinted changes in gene expression which thereby alter morbidity in middle age); these fascinating hypotheses stem from surveillance. Infant mortality rates are being linked to birth and placental weights and to insulin resistance in early adult life. An individual’s susceptibility to obesity, hypertension and mortality from heart disease in middle age is also now being associated with early nutrition (Barker et al. 1990). Thus, fascinating new aspects of science as well as issues of immense significance in public policy emerge from the general surveillance field.