Anthropometry is simple, non-invasive, quick and reliable form of obtaining objective information about a person’s nutritional status.

Weight

An upright beam scale may be used for older people. A movable wheelchair balance beam scale can be used for those who can only sit. A bed scale should be available in geriatric hospital for measuring the weight of bed-ridden patients. Weight less than 20% of the ideal body weight indicate a significant loss of total body protein requiring immediate action and investigation.

Height

Height should be measured in an upright position for the elderly who are agile and without stooped posture. Knee height (using a knee height caliper) in a recumbent position can be used to estimate stature, when it cannot me measured in upright position. Stature can be calculated by the given formulae:

Stature for men = (2.02 x knee height) – (0.04 x age) + 64.19
Stature for women = (1.83 x knee height) – (0.24 x age) + 84.88

The knee height measurement in these equations is in centimeters, and the age is rounded to the nearest whole year

Anthropometric indices

BMI has been used widely to estimate total body fatness. BMI can be estimated by using the formula:

BMI = weight (kg)/Height (m2)

The International Classification of adult underweight, overweight and obesity according to BMI

Classification	BMI(kg/m)
	Principal cut-off points	Additional cut-off points
Underweight	<18.50	<18.50
Severe thinness	<16.00	<16.00
Moderate thinness	16.00 - 16.99	16.00 - 16.99
Mild thinness	17.00 - 18.49	17.00 - 18.49
Normal range	18.50 - 24.99	18.50 - 22.99
		23.00 - 24.99
Overweight	≥25.00	≥25.00
Pre-obese	25.00 - 29.99	25.00 - 27.49
		27.50 - 29.99
Obese	≥30.00	≥30.00
Obese class I	30.00 - 34-99	30.00 - 32.49
		32.50 - 34.99
Obese class II	35.00 - 39.99	35.00 - 37.49
		37.50 - 39.99
Obese class III	≥40.00	≥40.00

Source: Adapted from WHO, 1995, WHO, 2000 and WHO 2004

BMI values are age-independent and the same for both sexes. Height and weight have co-efficient of variations in the order of less than 1%, may be altered by kyphosis in the aged and make interpretation of BMI invalid.
The Body Mass Index (B.M.I.) of an elderly individual tends to vary as a function of his or her age. Men typically experience a decline in B.M.I. as they grow older. The decreasing B.M.I. of men may have to do with a decrease in lean body mass over the course of time; lean body mass is something that men have generally had a greater quantity of than women throughout their lives.

Specific assessment tools of nutritional status designed for the elderly

Mini nutritional assessment (MNA)

The MNA was developed to evaluate the risk of malnutrition in the elderly in general practice and upon admission to a nursing home or hospital. It consists of a general health assessment, a dietetic assessment, anthropometric measurements, the patient’s subjective assessment, and global evaluation. Global evaluation includes questions on living independently, prescription drug use, psychological stress, acute disease, mobility, dementia, and skin conditions. The MNA is a very simple non-invasive, easy to administer, patient-friendly, non-expensive, very sensitive, highly specific, reliable and validated screening tool for malnutrition in the elderly. According to the developmental study, it was shown to have an accuracy of 92% compared with clinical evaluation performed by two physicians specialized in nutrition, and of 98% when compared with a comprehensive nutritional assessment, including biochemical tests, anthropometric measurements and dietary assessment. This tool does not involve biochemical tests, which showed no added benefit when validation tests were performed. (Nutr Rev 1996;54:S59±65)

Nutritional Screening Initiative

The NSI is a multidisciplinary effort of the American Dietetic Association, the American Academy of Family Physicians, and the National Council on Aging, to promote routine nutrition screening in health and medical care settings and thereby to raise awareness of risk of malnutrition among the elderly. This initiative incorporates screening and assessment at three levels. The first is a checklist designed to be self-administered (but can be completed by the caregivers) and consists of 10 scored (according to their importance) yes/no questions describing warning signs of poor nutritional status. The questions cover dietary assessment (the number of meals, food and alcohol intake, and autonomy in preparing food or feeding), general assessment (medical condition, medications, oral health, and weight loss), and social assessment (economic hardship, and rare social contact) . The validity of the checklist was examined by retrospective and prospective studies. Individuals with higher scores were more likely to have the poorest levels of nutrient intake and an increased risk of morbidity. The NSI checklist is a brief, easily scored screening tool that can identify community-dwelling elderly subjects at risk for low nutrient intake and health problems. (J Am Diet Assoc 1991;91:783±7).

NuRas

The NuRaS was developed and validated by German investigators, like the American NSI, to enhance physicians' awareness of nutritional problems in hospitalized elderly. This assessment scale is a simple and reliable screening tool for malnutrition and can be implemented as part of a comprehensive geriatric assessment. It consists of 12 items relating to gastrointestinal disorders, chronic diseases with pain, immobility, alterations in body weight, appetite, difficulties in eating, medication, cognitive or emotional problems, medication, smoking and drinking habits, and social situation. At a cut-off score of more than 4 points, older persons should be considered undernourished. Likewise, the scale facilitates therapeutic interventions by identifying treatable risk factors that might have contributed to the poor nutritional status. The scale usefulness has been shown in hospitalized patients and its applicability in other settings still needs to be tested. In addition, further investigations are still necessary to prove its predictive validity (Ann Nutr Metab 1995;39:340±5).

SCREEN

The Canadians, in an endeavor to develop a simple, feasible, valid and reliable screening tool for determining nutritional risk in community dwelling seniors, devised a 15-item questionnaire, SCREEN (Seniors in the Community: Risk Evaluation for Eating and Nutrition), that can be self- or interviewer- administered. The questionnaire items include weight change; the number of limited or avoided foods; frequency of eating; the consumption of fruits and vegetables, meat, milk and milk products, and fluids; chewing, biting and swallowing food; eating alone; meal replacements (such as Ensure); appetite; money for food; cooking; and shopping. It has been shown to have content validity and internal and test-retest reliability. Subsequently construct validity as compared with clinical judgment has been proven (J Gerontol 2001:56A:M552±8).