Dietary assessment is the process of evaluating what people eat by using one or several intake indicators.
Dual-energy X-ray absorptiometry DEXA is considered by many to be the criterion standard for assessment of percentage of body fat but has been shown to overestimate in those with a high fat percentage and to underestimate in those with low fat percentage.
Whole-body scans can be used to directly measure fat and lean mass through x-ray attenuation. Subjects should lie supine on the scanner, their body in the center of the table within the scan-lines.
The head should be tilted just slightly back and arms placed flat to each side of the body, with fingers together. No part of the body should be overlapping. Once positioning is confirmed, the scan can begin. The subject should remain still until the scan is complete, indicated by the scan arm moving to the home position.
The machine then estimates body composition in 3 compartments fat mass, fat-free mass, and bone mineral. For obese subjects who do not completely fit on the scanner table, a hemi-scan protocol may be used. For this method, the subject lies on his or her right side, with left-sided body parts that do not fit on the scanner excluded by placement over the left side of the table.
Any left-sided body parts that are excluded can be estimated by doubling of right-sided data. Underwater hydrostatic weighing Hydrodensitometry, also known as hydrostatic or underwater weighing, was the criterion standard two-compartment fat and fat-free mass model of body composition before DEXA.
This method relies on the Archimedes principle to determine total body volume through difference in body weight in air and underwater. Air displacement plethysmography ADP uses methods similar to those of hydrostatic weighing for measurement of two-compartment body composition.
Subjects should void both the bladder and bowels prior to testing. Prior to placing the subject into the chamber, a two-point calibration should be performed with the chamber empty, then with a liter calibration cylinder. Once calibration is complete, the subject may enter the chamber and the door can be closed.
The subject remains still while body volume is measured. This should be performed at least twice or until 2 results agree to within mL. From these measures, body density is determined and percentage body fat estimated. It is generally safe, although it is not recommended in subjects with pacemakers.
The testing procedure for BIA varies depending on the device used.
In general, the subject should abstain from exercise or sauna within 8 hours of the procedure and alcohol intake within 12 hours of procedure.
Wet skin, as in diaphoretic or incontinent subjects, interferes with test results. Path of current flow depends on the device used and location of electrodes.
Electrode sites should be cleaned with an alcohol wipe, particularly if the skin is moist or covered with lotion. Once electrodes are in place, the analyzer can be turned on and resistance and reactance recorded.
From these measures, body-fat mass and fat-free mass can be estimated. Functional Measure of Nutrition Status: This technique is based on the impairment in muscle function that occurs in malnourished subjects. A handheld dynamometer is used to measure maximal hand-grip force, which correlates well with total body protein.
Ideally, the dynamometer used should have an adjustable handle to accommodate different hand sizes. The subject should squeeze the dynamometer with as much force as possible. According to the Southampton protocol, 3 trials should be performed on both the dominant and nondominant hands and the best of the 6 measurements used for comparison with age- and sex-adjusted standards.Nutrition assessment is the best way to determine whether or not people’s nutritional needs are effectively being met, once food is available and easily accessible.
Nutrition assessment provides timely, high-quality and evidence-based information for setting targets, planning, monitoring and. Find tools for assessing the dietary intake of individuals.
See also Dietary Assessment Instruments for Research. Nutritional Assessment A nutrition assessment is an in-depth evaluation of both objective and subjective data related to an individual's food and nutrient intake, lifestyle, and medical history.
Once the data on an individual is collected and organized, the practitioner can assess and evaluate the nutritional status of that person.
NCP Step 1: Nutrition Assessment. Purpose: The purpose of nutrition assessment is to obtain, verify, and interpret data needed to identify nutrition-related problems, their causes, and significance. It is an ongoing, nonlinearand dynamic process that involves data collection and continual analysis of the patient/client’s status.
Nutritional Assessment A nutrition assessment is an in-depth evaluation of both objective and subjective data related to an individual's food .
Nutritional assessment is a comprehensive evaluation done to define a person's nutrition status. Assessment includes gathering information from the person's medical history, dietary history, a physical examination, anthropometric measurements, and laboratory tests.