Dietary assessment - Diet history
The development of the dietary history is usually attributed to Burke (1947). The method is a detailed retrospective dietary assessment used more often in clinical practice than in research studies. A diet history is used to describe usual food and/or nutrient intakes over a relatively long period e.g. 6 months and typically one year. Several Scandinavian studies have used the dietary history method in studies in older people (de Vries 2008 and Rothenberg 2008) and it was the dietary assessment method of choice in a large international cohort study known as SENECA, Survey in Europe in Nutrition and the Elderly Concerted Action, which was undertaken in twelve countries with 2600 respondents (van Stavern et al, 2002).
A dietary history is a structured interview method consisting of questions about habitual intake of foods from the core (e.g. meat and alternatives, cereals, fruit and vegetables, dairy and ‘extras’) food groups in the last seven days. This is followed by a ‘cross check’ to clarify information about usual intake in the past 3, 6, or 12 months, depending on the aims of the assessment. Traditionally it would include a 3-day record which is often now omitted (Ruitishauser and Black, 2002), or may be replaced by a 24-hour recall. Usual portion sizes are generally obtained in household measures and / or the use of photographic aids. In the SENECA study a modified diet history was utilised. This comprised a 3-day food record and a meal-based list of foods to check the usual consumption of the previous month. Portion sizes were based on standard portion sizes or checked by weighing.
In a small subsample, the SENECA study compared nutrient intakes obtained by a dietary history to those obtained by a weighed diary. Reported energy intakes were higher but less than energy expenditure measured by indirect calorimetry (van Stavern et al, 2002). An earlier study compared energy intakes obtained by weighed dietary records and diet histories to energy expenditure estimates obtained by doubly labelled water in children and adolescents (Livingstone et al, 1992). Mean energy intakes were biased towards overestimation, the differences were small and the authors concluded that the energy intake obtained by a diet history was more representative of habitual intake than the weighed diet diary.