Nutritional Assessment Report - Essay Example

? The present paper intends to make a strong understanding and conceptual discussion on the nutritional assessment of human beings. .By reviewing on the existing literature, a concrete and brief discussion has been done on the concepts like energy, food intake measures of food intake, energy balance and requirements and energy expenditure. The interrelationship between food intake and energy expenditure has also been analyzed in the paper. For getting a thorough understanding and make comparisons, practical experiments have done by using two methods of measurements of food intake and expenditure. Two types of methods have been used to measure food intake: precise weighed food record and 24-hour recall methods. 25 persons have been selected as sample size for the analysis BMR and total energy expenditure have also been found out. For understanding the nature and interrelationship between the variables, statistical tools like descriptive statistics, correlation and regression methods have been used. . The regression results show that the interrelationship between energy intake and total energy expenditure is statistically significant and the weighed energy intake seems to have strong relationship with TEE while that of recall energy intake seems to be insignificant. The energy expenditure indicators of BMR and total energy expenditure has also got significant statistical relationship and the total energy expenditure seems to be highly dependent on the BMR. Comparisons with FAO estimates, it is seen that our sample population does not have required energy expenditure as suggested by FAO. The BMR of our sample population also seems to be lower than that of FAO estimates. Introduction Nutritional status or energy of any person is measured in terms calories and calorie is hence known as the currency of nutrition and energy (Prentice, 1997). Energy keeps any mammal warm and drives all the activities of life. Energy is derived from the process of ‘chemical combustion’ of food intake which requires oxygen and produces carbon dioxide and water. Sufficient supply of food intake is needed for this process (Titchenal, 1988). The energy component of the food can be divided into chemical energy and metabolizable energy. Chemical energy of the food is the total energy which is liberated if it is combusted in oxygen. That is, its heat of combustion is normally the chemical energy and it can simply measured in a bomb calorimeter. The chemical energy is otherwise known as the gross energy (Durnin and Passmore, 1967; Cox 2005). The metabolic part of the total energy of the food is known as the megabolizable energy. Due to several reasons, a portion of the total energy of food intake would not be available for the body metabolism. The portion of the total energy which is digested and absorbed by the body is megabolizable energy or digestible energy. In the dietary and energy expenditure discussions, this metabolizable or digestible energy becomes relevant (Prentice, 1997; Gibney etal 2002; Lee and Nieman ,2003; Gibson ,2005). Objective and Methodology The present paper intends to make a strong understanding and conceptual discussion on the concepts energy, energy balance, energy requirements and energy expenditure. The interrelationship between food intake and food energy expenditure has also been analyzed in the paper. Hence, the main objectives of the paper are: 1) to integrate the understanding on the concepts like measures of intake, energy balance, requirements and expenditure 2) to give practical experience in methods of measurements of food intake and expenditure 3) to examine the interrelationship between these variables. Methodology For achieving the above said objectives, a concrete and brief discussion has been done on the concepts like measures of food intake, energy balance and requirements and energy expenditure. Practical experiments have been done on the measurements of food intake and energy expenditure. Two types of methods have been used to measure food intake: precise weighed food record and 24-hour recall methods. 25 persons have been selected as sample size for the analysis BMR and total energy expenditure have also been found out. For understanding the nature and interrelationship between the variables, statistical tools like descriptive statistics and regression methods have been used. (see the results as attached in the separate file). Measures of Food Intake Food intake is not a single or simple measure of one variable like weight or height, but the variables or indicators regarding many items of food intake. Food intake data take different foods at different times in different places into consideration. The food intake information have to be collected in different combinations with many different preparation methods from different people at different times. It is difficult to capture the truth and facts about food intake as the validity of the data is relied on the individuals who eat the food. All traditional food intake methods depend on the information reported by the individuals or respondents themselves, though some methods give more space to the investigators for the data collections, directions, weighing of different items etc. The two methods of food intake measurement which are considered for the present analysis are: 1. Precise Weighed Food Record and 2. 24 Hour Recall (Becker and Helsing, 1991; Cameron and Staveren,1988) Precise Weighed Food Record Food intake of the respondent is asked to be reported each time and each day for obtaining food record. Normally food records are gathered for 3 to 7 days. 7 days methods are usually known as “Gold Standard” as food record for 7 days may be used for validating other methods. Food record is based on the simple assumption that the self reported information is valid and correct, though many weaknesses have been found with advent of biomarkers. Body fluids and tissues are measured by biomarkers which independently reflect different components of food intake. For attaining reliable food records, it is assumed that the information is collected from literate and motivated subjects. The quality of the record has inverse relationship with the number of days recorded as the burden of the record is mostly on the subjects. Sometime, actual process of recording of food intake may lead to the change in the food patterns of the subjects. In a weighed food record method, the ingredients used in the preparation of each meal or snack and the individual portions of the prepared food are weighed. Wastage of food during the preparation , service or consumption of food is also weighed. This approach is referred to on the Precise Weighing Record and this process of weighing is usually done by the investigators rather than the respondents themselves. Hence, the process is very labor intensive, time consuming and expensive as the main burden of collection is heavily on the investigators. Certain data on cooked and mixed dishes are given in food consumption tables for assessing the contaminants of the food intake (Maclntyre, 2009). 24 Hour Recall Method By 24-hour recall method, the current nutrient intakes are quantitatively assessed. The collection of information on food intake is conducted in person or by telephone and this method requires only short-term memory, as is asked to the respondents to disclose the information on the food intake of the last 24 hours. The investigator collects the information in the form of a structured interview and asks all the members of the family (including children) to recall all food and drink during the previous 24 hours. This method of data collection relatively brief with 20-30 minutes and the burden on the subjects is also less compared with food records. Hence, this method is appropriate for collecting information from illiterate or low-income population as the subjects need not to read or write for recalling. The main weakness of the 24-hour recall method is that a single day’s diet can not describe the usual diet and generalizations may lead biased results (Maclntyre,2009). The Concepts of Energy Balance and Energy Requirements Energy balance is the state in which total ‘energy in’ is equal to the total ‘energy out’. What is eaten and drunk is ‘energy in’ and what is burnt through any physical activity is ‘energy out’. When calories consumed through food intake reach in balance with calories burned through any physical activity, the state of energy balance is achieved. Maintaining energy balance, energy in as well as energy out is equally important. Though having same and equal food intake, people who are more physically active will have more energy out than those who are physically inactive (Webb etal 1980). Energy Balance Amount of energy in (calories consumed) = Amount of energy out (calories burned). Positive Energy Balance Amount of energy in (calories consumed)> Amount of energy out (calories burned Negative Energy Balance Amount of energy in (calories consumed)< Amount of energy out (calories burned Calorie requirement is the amount of calories needed to maintain energy balance and healthy body weight. The calorie estimates are different for different age and gender groups at different levels of activity (sedentary, moderately active or active). The calorie estimates are usually determined by Institute of Medicine (IOM) and the estimates of IOM are about rounded to the nearest 200 calories (James and Schofield, 1990). Measures of Energy Expenditure There are three parts to total energy expenditure (TEE) in human beings;1) Basal Metabolic Rate (BMR), 2) Thermic Effect of Food and 3) the Energy Expenditure of activity (thermogenesis) . Among these components, BMR is the most commonly used indicator of total energy expenditure as it is the major component of TEE and it is the energy expended when an individual is at complete rest and at the post absorptive state in the morning just after sleep. BMR accounts for approximately 60 percent of the total daily energy expenditure in individuals having sedentary occupations. Thermic effect of the food, which is approximately 10 percent of TEE, is related with digestion, absorption and storage of food. Activity thermogenesis, which is directly related with physical exercises is divided into exercise and non exercise activities (Weir 1949; Levine etal, 2000). The exercise related thermogenesis will be equal to almost zero in most of the individuals as the purposeful physical exercise is almost rare and for those who do regular exercise, it will be around 10 percent of the total energy expenditure. The rest of the total energy expenditure accounts for the non-exercise thermogenesis. It consists of the combined energy costs of the daily physical activities of living, moving around, spontaneous muscle contraction and maintaining postures. The energetic needs of altered temperature, medications and emotions also consist of the non-exercise thermogenesis. These components of the energy expenditure highly variable and the variability depends on the differences of daily energy expenditure between individuals. Indirect and direct calorimetric and non-calorimetric methods are used for the measurement of total energy expenditure. And these measurements of energy expenditure are applied to assess the relative metabolic needs, fuel utilization and the relative thermic effect of food intake at different components (Cunnigham, 1990; Kurpad etal 1997;. Levine2005; Murgeatroyd etal 1993) Nature and Interrelationship between the Food intake and Energy Expenditure The nature and relationship between the food intake and energy expenditures have been analysed with the help of statistical tools like descriptive data, correlation and regression methods. The sample size of the participants is 25 in number and the average weight is 62.5 kg with the minimum of 45 and maximum of 82 kg. The skewness values and histograms show that except protein intake, all the variables are normally distributed both in recall and weighted methods. It is interesting to see that the average value of the energy measured both by weighed and recall methods is the same (see table 1). The relationship between the variables found out by both the methods (recall and weighed method) are shown by both correlation and regression methods. The regression coefficients in all cases seem to be significant. There exists strong relationship between energy weighed and energy recall as well as between weighed protein intake and recall protein intake with the p-value of 0.001. The Pearson correlation coefficients between these variables indicate that correlation between all the variables are significant and more than 60 percent in all the cases (Table 5). The only variable which has no any correlation between other variables is weight. . Again, it is seen that there is strong relationship between food intake and energy expenditure. The impact of food intake on the total energy expenditure is significant when weighed energy method is used for measuring the food intake. The regression result between weighed energy intake and total energy expenditure is statistically significant while the impact is not significant when the 24-hour recall method is used. (see table 7 and 8). The energy expenditure indicators of BMR and total energy expenditure has also got significant statistical relationship as per the regression results (see table 2). The total energy expenditure seems to be highly dependent on the BMR. It can be drawn from the regression table that , total energy expenditure seems to be higher among participants with higher BMR and the energy levels seem to be lower among the ones with lower BMR. Comparison With FAO Values Though in our results, different age and weights are not given separately, the following tables show a comparative picture of our study results with FAO estimates. The student with the weight of 62.52 kg, has got the BMR value of 5.94 while the children with the weight of 64.4 kg requires BMR of 7.52 and TEE of 13.9 MJ/day. Variable Minimum Maximum Mean Weight 45 82 62.52 BMR (MJ/day) 4.88 7.38 5.94 Total energy expenditure (MJ/day) 5.36 13.81 9.30 Compiled by the researcher Variable FAO ESTIMATES Weight 42.3 53.8 64.4 67.8 BMR (MJ/day) 5.88 6.74 7.52 7.77 Total energy expenditure required (MJ/day) 10.66 12.51 13.9 14.270 Source: FAO (2004) Even the person with a weight of 42.3 kg requires the BMR of 5.88 and TEE of 10.66 MJ/day while as per our estimate the child with the weight of 45 has got the respective values as 4.88 and 5.36 respectively, which are far below what are required. Conclusion It is seen from the empirical analysis that there exists strong statistical relationship between different measures of food intake as well as `between different energy expenditures. The statistical results show that food intake measurements by using both the methods are more or less equal and hence, both the methods are equally important in the energy and food intake measurement. 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