Dietary Assessment Methods Essay

A dietary assessment method is a critical component in many aspects of nutritional epidemiology such as evaluating energy and nutrient intake in free-living individuals (Taren, et al., 2002). The purpose of dietary assessment data collection is to establish the causal associations between diet and disease aetiology (Jain, et al., 1996). However, it is very difficult to measure exactly how much food people eat or to determine the nutrient content of the diet (Wild, et al., 2001). Therefore, the valid and precise techniques are required to estimate accurate and detailed information on food and nutrient intake as well as eating patterns for identification of the dietary influence on health and disease (Bingham, et al.,1994).

Nutrition assessments

The majority of retrospective dietary assessment methods such as 24-hour recall is of limited validity because of dependence on subject memory and motivation, reliability of the respondent not to under /misreport and ability to estimate portion sizes of the items consumed (Thompson & Byers, 1994). Although the technique is inexpensive, low respondent burden and relatively easy to assess current nutrient intake of a group, it is not appropriate to use data from a single day to represent an individual’s usual intake due to day to day variation (Johnson,

It has been associated with many factors such as age, sex, and body mass index, as well as other demographic and psychological factors (Johansson, et al., 2001).Several studies found that obese subjects tend to underestimate their energy intake more often and more severe than lean subjects (Johnson, 2002). Although various methods exist for dietary assessment, an ideal tool does not exist to measure nutritional status accurately (Olafsdottir, et al., 2006). Each method has merits, biased, correlated errors and practical difficulties to be considered when choosing one method above another (Thompson & Byers, 1994, Olafsdottir, et al.,