Dietary Assessment Essay -- Nutrition, Diet, Disease

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 include clinical and dietary assessment, anthropometrics, as well as biochemical, laboratory immunologic and functional indices of nutritional status (Gibney, 2005). In epidemiological studies, different dietary investigation tools were designed to assess the nutritional status in individuals and populations, nutrition monitoring and surveillance and diet-disease research (Friedenreich, et al., 1992, Taren, 2002). Choosing an appropriate dietary assessment method depends on the purpose for which it is needed. 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 repr... ...., 2006). Furthermore, nutritional analysis of recording or reporting food intake data presents a main source of inaccuracy when determining habitual nutrient intake and it does not contain comprehensive information on the interpretation of results from dietary surveys (Macdiarmid, & Blundell, 1997). Therefore, biochemical markers of nutrient intake are now a valuable tool in validating dietary assessment methods (Bingham, 2002). For example, the double labelled water technique and 24-hour urine nitrogen and potassium are routinely used and potentially independent of the errors associated with dietary survey methods (Bingham, 2002). The aims of the study is to determine the intake of total energy, protein , carbohydrate, fat, iron, calcium and fiber within a group of students using the duplicate diet analysis, 24 hour recall and the 7 day weighed intake.