Methodology of dietary assessment in athletes: concepts and pitfalls.

Abstract

Evaluation of an athlete's diet is important in both clinical practice and research. The main purpose of this review is to provide health professionals with guidance regarding the special issues that are likely to be encountered when assessing the dietary intake of sportspersons. A number of methods may be used for the dietary assessment of individuals and/or groups of athletes, including retrospective (diet recall, food-frequency questionnaire, and diet history) and prospective (diet record, duplicate portion) techniques. A 3-4-day estimated diet record is the most widely used approach, but collection of single or multiple diet recalls is also common. Care must be taken, however, to ensure that days of diet monitoring accurately reflect usual food consumption during the period of interest. Under-reporting of habitual energy intake is widespread among athletes, and its magnitude should be carefully addressed when interpreting the results of dietary assessment. Other issues, specifically related to sportspersons, that are often neglected include adequacy of standard portion sizes, frequency of snacking, fluid intake, supplement use, weight-control practices, and seasonality of sport activities and food consumption. There are subtle methodological differences in the dietary assessment of athletes and non-athletes, which, when taken into consideration, may substantially increase the quality of intake data and optimise the outcome of dietary intervention.