Why is it important to improve dietary assessment
Food frequency questionnaires, which measure a person's usual intake over a defined
period of time, and 24-hour recalls, in which a person records everything eaten or drunk
during the previous 24 hours, are commonly used to collect dietary information. Short
screeners, which include just a few questions about consumption of selected items, can be
useful in situations that don't require assessment of the total diet or when resources are
Accurately measuring dietary intake through these methods is crucial to understanding
the role of diet in causing and preventing chronic diseases such as cancer, heart disease,
and diabetes. Dietary recommendations aimed at encouraging people to follow dietary
patterns to promote health and reduce disease risks are based in part on information
gathered through these means.
The problem is that these dietary assessment instruments are subject to substantial
error, both random and systematic. In addition, people don't always report accurately.
So, it's important to design these instruments so that they collect the most accurate
information possible and to validate them before use. NCI staff used extensive cognitive
testing in developing the DHQ and these short screeners so as to make them easier to use
and to improve their performance.