Dietary assessment methods: dietary records.

Dietary records or food diaries can be highlighted among dietary assessment methods of the current diet for their interest and validity. It is a prospective, open-ended survey method collecting data about the foods and beverages consumed over a previously specified period of time. Dietary records can be used to estimate current diet of individuals and population groups, as well as to identify groups at risk of inadequacy. It is a dietary assessment method interesting for its use in epidemiological or in clinical studies. High validity and precision has been reported for the method when used following adequate procedures and considering the sufficient number of days. Thus, dietary records are often considered as a reference method in validation studies. Nevertheless, the method is affected by error and has limitations due mainly to the tendency of subjects to report food consumption close to those socially desirable. Additional problems are related to the high burden posed on respondents. The method can also influence food behavior in respondents in order to simplify the registration of food intake and some subjects can experience difficulties in writing down the foods and beverages consumed or in describing the portion sizes. Increasing the number of days observed reduces the quality of completed diet records. It should also be considered the high cost of coding and processing information collected in diet records. One of the main advantages of the method is the registration of the foods and beverages as consumed, thus reducing the problem of food omissions due to memory failure. Weighted food records provide more precise estimates of consumed portions. New Technologies can be helpful to improve and ease collaboration of respondents, as well as precision of the estimates, although it would be desirable to evaluate the advantages and limitations in order to optimize the implementation.