Caballero B. (ed.) Encyclopaedia of Food Science, Food Technology and Nutrition. Ten-Volume Set

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energy-dense diet leading to excess energy intake and

lack of physical activity. There is abundant evidence

that obesity is associated with a high risk of coronary

heart disease, hypertension, diabetes mellitus, and

gastrointestinal disorders. The risk of cancers of a

number of sites (endometrial, renal, colon, gallblad-

der, and postmenopausal breast cancer) is also linked

to obesity. As treatment of obesity is difficult, the

need to readjust dietary energy intakes and/or phys-

ical activity permanently is essential. Other health

advantages of high levels of physical activity include

improved mental and psychological health.

0055 Only 17% (six of 35) of member states made refer-

ence to the importance of increasing physical activity

(Armenia, Estonia, Malta, Poland, Sweden, and the

UK). Environments which support improved eating

habits and more active living are needed. It is rec-

ommended that prevention efforts are focused on

population-based public health strategies.

Conclusion

005 6 Cooperationandcollaborationareneededthroughout

Europe and there is a need to share information and

build alliances. In western Europe there exists the

European Academy of Nutritional Sciences (EANS),

the Federation of European Nutritional Sciences

(FENS), and the Arbeitsgemeinschaft Erna

hrungsver-

halten/Working Association for Nutritional Behavior

(AGEV)andmanycountries havetheirNutritionSoci-

ety.In CIS and CCEE there seems tobe a lack of coord-

ination, and nutrition networks or societies should be

established to facilitate sharing of information and

developments in the area of food and nutrition.

Seealso: Anemia (Anaemia):Iron-deficiencyAnemia;

European Union:EuropeanFoodLawHarmonization;

Exercise:MetabolicRequirements; Folic Acid:

PropertiesandDetermination; Food Poisoning:

Statistics; Food Safety; Infant Foods:MilkFormulas;

Infants:Breast-andBottle-feeding; Iodine:Iodine-

deficiencyDisorders; Obesity:Epidemiology; Quality

Assurance and Quality Control; Salmonella:Properties

andOccurrence; World Health Organization; Obesity:

Epidemiology World Trade Organization

Further Reading

Adams JS and Lee G (1997) Gains in bone mineral density

with resolution of vitamin D intoxication. Annals of

Internal Medicine 127(3): 203–206.

Agra Europe (1997) East Europe Agriculture and Food.

No. 179. London: Agra Europe.

Bates CJ (1997) Plasma total homocysteine in a representa-

tive sample of 972 British men and women aged 65 and

over. Clinical Journal of Nutrition 51: 691–697.

Braga C (1997) Homocysteine as a risk factor for vascular

disease. Nutrition Research Newsletter 16: 7–8.

Borgdorff MW and Mortarjemi Y (1997) Surveillance of

Foodborne Diseases: What are the Options? WHO/FSF/

FOS/97.3. Geneva: WHO.

Brenner BM (1982) Dietary protein intake and the progres-

sive nature of kidney disease: the role of hemodynami-

cally mediated glomerular injury in the pathogenesis of

progressive glomerular sclerosis in ageing, renal absorp-

tion, and intrinsic renal disease. New England Journal of

Medicine 307: 652–659.

CARAK newsletter (1997). Geneva: WHO.

Consumers in Europe Group (1994) The Common Agricul-

tural Policy: How to Spend £28 Billion a Year Without

Making Anyone Happy. London: Consumers in Europe

Group.

FAO statistical databases (FAOSTAT DATA): http://apps.-

fao.org/cgi-bin/nph-dp.pl.

Health Education Authority (1996) Folic Acid – What all

Women should Know. UK: Health Education Authority.

Health Education Authority (1997) Folic Acid and the Pre-

vention of Neural Tube Defects: A Summary Guide for

Health Professionals.

Hecht K and Steinman E (1996) Improving Access to Food

in Low-income Communities: An Investigation of Three

Bay Area Neighborhoods. San Francisco: California

Food Policy Advocates.

Itoh R, Nishiyama N and Suyama Y (1998) Dietary protein

intake and urinary excretion of calcium: a cross-

sectional study in a healthy Japanese population. Ameri-

can Journal of Clinical Nutrition 67: 438–444.

James WPT (1997) An Interim Proposal on the Creation of

a UK Food Standards Agency. London: FSA.

James WPT, Nelson M, Ralph A and Leather S (1997) The

contribution of nutrition to inequalities in health. British

Medical Journal 314: 1545–1549.

ferstein FK and Clugston GA (1995) Human health

problems related to meat production and consumption.

Fleischwirtschaft 75(7) 75–77.

Leather S (1996) The Making of Modern Malnutrition: An

Overview of Food Poverty in the UK. London: Caroline

Walker Trust.

Marriott BM (1997) Vitamin D supplementation: a word of

caution (editorial). Annals of Internal Medicine 127(3):

231–232.

Motarjemi Y and Ka

ferstein F (1996) International Con-

ference on Nutrition: A Challenge to the Food Safety

Community. 1996 WHO/FNU/FOS/96.4. Geneva:

WHO.

National Food Alliance (1995) Food and Low Income: A

Conference Report. London: National Food Alliance.

National Research Council (1997) Premature Death in the

New Independent States. London: National Academy

Press.

Proceedings of Regional Conference on Elimination of IDD

in Central and Eastern Europe, the Commonwealth of

Independent States, and the Baltic States (1997)

Munich, Germany.

Report of a Working Party to the Chief Medical Officer for

Scotland (1993) Scotland’s Health – A Challenge to us

4174 NUTRITION POLICIES IN WHO EUROPEAN MEMBER STATES

all: The Scottish Diet. Scottish Office Home and Health

Department.

Reports of the Scientific Committee for Food (1993) Nutri-

ent and Energy Intakes for the European Community.

Luxembourg: Commission of the European Commu-

nities, Directorate-General Industry.

Report of the Working Group on Diet and Cancer of the

Committee on Medical Aspects of Food and Nutrition

Policy (1998) Nutritional Aspects of the Development of

Cancer. Department of Health report no. 48. London:

Stationery Office.

Robertson A (1997) Priorities for Eliminating IDD in

CCEE and CIS. Regional Conference on Elimination of

IDD in Central and East Europe, the Commonwealth of

Independent States, and the Baltic States. Munich,

Germany.

SAFE Alliance (1997) The Common Agricultural Policy

Yesterday, Today and Tomorrow. London: SAFE

Alliance.

Third European Interdisciplinary Meeting and 20th Annual

Scientific Meeting of AGEV (1997) Public Health and

Nutrition. Abstract book. Copenhagen: AGEV/WZB.

USDA (1997) Russian Food Consumption: Emerging

Demand for Quality. Newly Independent States and

Baltics Update. Agriculture and Trade Report. Economic

Research Service WRS-97-S1.

WHO (1990) Diet, Nutrition, and the Prevention of

Chronic Diseases: Report of a WHO Study Group.

Geneva: WHO Technical Report Series no. 797.

WHO (1996) Guidelines for Strengthening a National

FoodSafetyProgramme. WHO/FNU/FOS/96.2.Geneva:

WHO.

WHO (1997) Food Safety and Globalization of Trade in

Food: A Challenge to the Public Health Sector. WHO/

FSF/FOS/97.8. Geneva: WHO.

WHO (1997) Prevention and Management of the Global

Epidemic of Obesity: Report of the WHO Consultation

on Obesity. WHO/NUT/NCD/97.2. Geneva: WHO.

WHO (1998) Comparative Analysis of the Implementation

of the Innocenti Declaration in WHO European

Member States. Copenhagen: WHO Regional Office.

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WHO website: http://www.who.ch/ and Health for All:

http://www.who.dk/www.who.dk/mainframe. htm.

Wilkinson RG (1996) Unhealthy Societies; The Afflictions

of Inequality. London: Routledge.

Wiseman MJ (1987) Changing in renal function in response

to protein restricted diet in type 1 (insulin-dependent)-

diabetic patients. Diabetologia 30: 154–159.

World Cancer Research Fund in association with American

Institute for Cancer Research (1997) Food, Nutrition

and the Prevention of Cancer: A Global Perspective.

Washington: American Institute for Cancer Research.

Wretlind A (1982) Standards for nutritional accuracy of the

diet: European and WHO/FAO viewpoint. American

Journal of Clinical Nutrition 36: 366–375.

NUTRITIONAL ASSESSMENT

Contents

Importance of Measuring Nutritional Status

Anthropometry and Clinical Examination

Biochemical Tests for Vitamins and Minerals

Functional Tests

Importance of Measuring

Nutritional Status

F Fidanza, Universita degli Studi di Perugia,

Perugia, Italy

Aims of Nutritional Status Assessment

0001 Nutrition has been more and more implicated in

various health problems. Consequently, improving

nutritional status can play an important role in

solving or preventing these problems.

0002Malnutrition – both undernutrition and overnutri-

tion – is widespread both in single patients as well as

in population groups. Surgical patients, for example,

often suffer from protein-energy malnutrition, and

subclinical blood levels of vitamins and minerals are

present even in population groups of developed coun-

tries.(SeeMalnutrition: The ProblemofMalnutrition.)

0003But scientific interest is now moving from deficien-

cies to a new role for some micronutrients in the

maintenance of health and the prevention of degen-

erative diseases.

0004Efforts to obtain reliable information about the

nutritional status of both patients and population

NUTRITIONAL ASSESSMENT/Importance of Measuring Nutritional Status 4175

groups encounter many difficulties. There are several

reasons for these problems, the most important of

which is the body’s ability to adapt to adverse condi-

tions, so that changes in biochemical or functional

characteristics become evident only after substantial

impairment has occurred. Methods of assessment

must therefore be both highly specific and highly

sensitive.

0005 The complexity of the interactions between dietary

inadequacy, disease, and personal and environmental

variables also makes it particularly difficult to deter-

mine whether health impairment can be linked spe-

cifically to diet and whether or not any nutritional

deficiency is secondary to some other defects. These

problems can be solved only through continuing basic

research to expand knowledge of the patterns of bio-

chemical, physiological, pathological, and behavioral

responses to deficiencies or excess of nutrients and to

improve methods for applying this knowledge in

practical situations.

0006 Nutritional surveys can be cross-sectional (i.e.,

provide data on prevalence of malnutrition or defi-

ciency) or longitudinal (i.e., provide data on incidence

of malnutrition or deficiency and association with

other factors). The serial collection of data at popula-

tion level is a basic part of surveillance or of any

intervention program.

0007 A nutritional survey can be very general and com-

prehensive, in which case it includes the analysis not

only of the prevailing nutritional problems of a given

population but also of the responsible factors and the

consequences. On the other hand, a survey can also

be limited to some specific nutrients or selected popu-

lation or patient groups. The selection is made

according the objectives of the study and the funds,

personnel, and time available. (See Dietary Surveys:

Surveys of Food Intakes in Groups and Individuals.)

0008 Malnutrition, whether under- or overnutrition, de-

velops in various steps. In the prepathogenic period

information on dietary inadequacy can be obtained

from food balance sheets at national level and dietary

surveys at individual or group level. These can pro-

vide an indication of potential nutritional problems

of the population or group but do not assess the

problems.

0009 Late in the prepathogenic period some early changes

in the body nutrient reserves can be present, but

methods available are not sensitive enough to assess

them.

0010 In the pathogenic period, before the emergence of

clear clinical signs, body tissue nutrient levels are

modified to such a degree that metabolic and/or func-

tional alterations appear. Biochemical and functional

tests are then appropriate for status assessment and/

or diagnosis.

0011Once the clinical horizon has been reached, non-

specific clinical signs and symptoms are present. An-

thropometric measurements can be of some use early

at this stage, as can biochemical and functional tests.

0012When symptoms are present clinical nutrition as-

sessment and studies of morbidity data are of great

help. The final stage of the nutritional problem can be

assessed from analysis of mortality rates and data

from postmortem examination, but in this way only

information of retrospective conditions is obtained.

Sampling Procedure

0013In population studies if all the subjects cannot be

examined, a very careful sampling procedure has to

be chosen, considering first study design and then

sample size. Sampling details most appropriate for

each study design can be found in epidemiology text-

books. (See Epidemiology.)

Collecting and Storing Samples for Biochemical

and Immunological Tests

0014Once the population sample is selected it is necessary

to consider in great detail the collection and storage

of samples for biochemical and immunological tests.

0015The instructions for sample collection and prepar-

ation vary according to the specific assays to be per-

formed. Only general rules are provided here.

0016Body tissues and excretions can rapidly deteriorate

and/or be easily contaminated. In general, to obtain

whole blood, serum, or plasma, appropriate syringes

or vacuum collection tubes are used. If handled care-

fully, hemolysis can be avoided.

0017For some minerals and trace elements, in order to

avoid contamination, one must use new plastic (poly-

styrene or polypropylene) syringes and collection

tubes, and wear powder-free latex gloves when col-

lecting or working with specimens.

0018Urine samples must be acidified and chilled on ice

in polypropylene or polyethylene bottles.

0019Specimens of adipose tissue can be obtained by

microbiopsy or needle aspiration by vacuum tube

assembly.

0020The plasma or serum for protein determinations

can be stored for 1 month at 2–6



C and for several

months at 20



0021Lipid fractions immediately separated from serum

or plasma are stable for 1 year or more at 70



C, if

properly handled. Adipose tissue specimens for fatty

acid determination can be stored at 20



C without

any other precaution up to 18 months.

0022For most vitamin determinations, plasma or serum

is used and it can be stored at 20



C for several

months or, in a few cases, even for years. Samples

should be protected from light for fat-soluble

4176 NUTRITIONAL ASSESSMENT/Importance of Measuring Nutritional Status

vitamins and riboflavin analysis. For the enzymatic

assays of erythrocyte thiamin, riboflavin, and vitamin

heparinized blood should be stabilized with proper

ACD solution (ACD solution is a stabilizer made of

citric acid, sodium citrate and d-glucose) for storage

at 4–6



C for 10 days. For the erythrocyte thiamin

pyrophosphate (TPP) assay the determination should

be carried out within 2 h of drawing blood because of

TPP instability. For vitamin C determination, hepar-

inized blood, after stabilization with metaphosphoric

acid, can be stored frozen, preferably at 70



C, for

no more than 3 weeks. For vitamin C determination

by high-performance liquid chromatography (HPLC),

heparinized blood specimens can be stored for a

few weeks at 80



C after addition of reduced

glutathione within 20 min of collection. The addition

of dithiothreitol increases stability of plasma samples

to more than 1 year at 70



0023 Acidified urine specimens for thiamin, riboflavin,

and vitamin B

determinations are stable at 20



for 3 months. The specimens should be protected

from light. Longer storage is possible for biotin and

pantothenic acid.

0024 For mineral and trace element determination serum,

plasma, whole blood, or blood cells are used with no

great problems for storage, but glass containers

should be avoided.

0025 For cellular studies of immunocompetence the

blood must be rapidly processed; in some cases the

testing of frozen cells was successful.

Recommended Methods for Nutritional

Status Assessment

0026 Table 1 is a synopsis of some recommended methods.

For a detailed description of them as well as for other

methods, see the Further Reading section.

0027 These methods can be used for the whole popula-

tion as well as for single patients. In the clinical

setting, nutritional assessment and support are best

performed by a nutritional support team, including

clinician, nutritionist, and clinical chemist. If needed,

advanced methods for the assessment of body com-

position, nitrogen balance, and some prognostic in-

dices are available to detect patient malnutrition and

to predict outcome (sepsis, wound dehiscence, death).

Data Processing and Calculation

0028 The most important stages of data processing are:

coding (including a preliminary quality control);

data input; quality control data; data bank; data

analysis (using parametric and nonparametric tech-

niques); and reporting. Specialized books describe in

detail the above stages. For each type of variable,

specific calculation methods may be used. Only

general rules will be provided here.

0029For variables not normally distributed (some an-

thropometric data, ferritin, etc.), a logarithmic trans-

formation can be applied. In some cases the use of

nonparametric tests is preferred.

0030For the use and interpretation of anthropometric

measurements an Expert Committee Report of the

World Health Organization is highly recommended.

Technical framework and detailed guidance on the

use and interpretation of anthropometric measure-

ments in pregnant and lactating women, newborn

infants, infants and children, adolescents, overweight

and thin adults, and adults aged 60 years and over are

provided. An extensive series of reference data is

included in an annex.

0031Computer programs are now commonly used to

test specific hypotheses. Because of the highly special-

ized skills required for proper processing and analysis

of data, it is recommended that specialists in these

fields take part in the planning and execution of

evaluation. To improve the quality of this work it is

advisable that these specialists are also involved in the

data recording – an essential preliminary step of data

processing. This means that they must be involved in

the design of the study and in the preparation and

testing of various forms and/or questionnaires needed

for the study.

0032For data analysis, a data stratification by age

groups and sex or any other meaningful stratification

like altitude (for hemoglobin), socioeconomic status,

and health/disease data, must often be used. Results

may be expressed in terms of means and standard

deviations or standard errors or as percentages of

values (prevalence) above or below an arbitrary cut-

off point defining adequacy. Anthropometric indices

can be expressed in terms of Z-score (or standard

deviation score). If the sample size is large enough,

the percentiles or the frequency distributions are very

useful. This data presentation facilitates comparison

between surveys in different countries; it permits at

any time the selection of the percentile or the range of

percentiles of reference, i.e., acceptability, and it can

represent a combination of the descriptive and inter-

pretative ways for analyzing and presenting collected

data.

0033The final step is the interpretation of data. In gen-

eral the prevalence of malnutrition or deficiency is

obtained using cut-off from a reference population.

This reference population and the population under

study are often from different areas or the criteria

used to specify the reference population are not care-

fully defined. However, since most reference values

are population-specific, it is recommended that data

from a clinically healthy reference population of the

NUTRITIONAL ASSESSMENT/Importance of Measuring Nutritional Status 4177

tbl0001 Table 1 Nutritional status methodology

Item Assessed variable Method or apparatus

Anthropometry

Stature Height Anthropometer or stadiometer

Sitting height Anthropometer

Length Measuring table

Body mass Weight Beam scale

Circumferences Mid upper arm circumference (MAC) Flexible nonelastic tape

Head Flexible nonelastic tape

Chest Flexible nonelastic tape

Waist Flexible nonelastic tape

Hip Flexible nonelastic tape

Thigh Flexible nonelastic tape

Skinfold Triceps (TSF)

Skinfold calliper

Subscapular Skinfold calliper

Thigh Skinfold calliper

Diameters Biacromial breadth Anthropometer

Biiliac breadth Anthropometer

Bicondylar breadth Sliding calliper

Bistyloid breadth Sliding calliper

Derived indices Height for age Z-score

Weight for age Z-score

Weight for height Z-score

Body mass index Weight/height

Arm muscle circumference MAC - (p TSF)

Arm muscle area (MAC - (p TSF))

/4p

Waist/hip ratio

Waist/thigh ratio

Body composition

Atomic level Carbon Inelastic neutron scattering

Nitrogen Neutron activation analysis

Others Neutron activation analysis

Molecular level Water Isotope dilution technique or bioelectrical

impedance analysis

Osseous minerals Dual-photon absorptiometry

Protein as total body nitrogen Neutron activation analysis

Lipid Hydrodensitometry

Cellular level Body cell mass Total body potassium (TBK) or exchangeable

TBK

Extracellular fluid Dilutometry

Extracellular solids Indirect methods (total body Ca by neutron

activation analysis)

Tissue system Subcutaneous and visceral adipose tissue Computed axial tomography

Skeletal muscle mass Indirect methods (24-h urinary creatinine

or TBK)

Nitrogen Indirect method (neutron activation

analysis)

Whole body Body mass See anthropometry

Stature See anthropometry

Circumferences See anthropometry

Skinfolds See anthropometry

Densitometry Underwater weight

Physical working capacity

and physical fitness

Cardiorespiratory efficiency Treadmill or bicycle ergometer

Muscle strength Dynamometers

Motor performance Several tests

Energy balance Energy intake Individual dietary surveys

Energy expenditure Indirect calorimetry

Doubly labeled water

Lipid

Essential fatty acids Serum, erythrocyte membranes,

subcutaneous fat tissues

Gas chromatography

Protein

Transport proteins Plasma or serum Immunological

Fibronectin Plasma Laser nephelometry

Albumin Plasma or serum Dye-binding

Continued

4178 NUTRITIONAL ASSESSMENT/Importance of Measuring Nutritional Status

Item Assessed variable Method or apparatus

Creatinine Urine Colorimetric (autoanalyser)

HPLC

3-Methyl histidine Urine Colorimetric or fluorometric

HPLC

Somatomedin C (IGF-1) Plasma or serum Radioimmunoassay

Amino acids Plasma Automated ion exchange

HPLC

Vitamins

Vitamin A (retinol) Plasma or serum

b,c

HPLC

Carotenoids Plasma or serum

HPLC

Vitamin E (a-tocopherol) Plasma or serum

HPLC

25 (OH)-vitamin D Serum Competitive protein-binding

HPLC

RIA

Vitamin K

(phylloquinone) Serum or plasma HPLC

Thiamin Erythrocytes Transketolase activity

Whole blood HPLC

Urine

Fluorometric

Thiamin pyrophosphate Erythrocytes HPLC

Riboflavin Erythrocytes Glutathione reductase activity

Urine

HPLC

Flavin adenine dinucleotide Whole blood HPLC

Niacin Whole blood Microbiological

Niacin metabolites Urine

HPLC

Vitamin B

Erythrocytes Aspartate transaminase activity

Pyridoxal 5

phosphate Whole blood HPLC

Pyridoxal 5

phosphate Plasma Radioenzymatic

4-Pyridoxic acid Urine

HPLC

Folate (5-Me-THF) Serum or plasma

Competitive protein-binding

Erythrocytes Radioassay

Homocysteine Plasma HPLC

Vitamin B

(cobalamins) Serum or plasma Competitive protein-binding

Methylmalonic acid Serum or urine GC-MS

Biotin Whole blood Microbiological

Plasma/urine Radioimmunoassay

Pantothenic acid Whole blood Microbiological

Vitamin C Plasma/buffy coat layer Spectrophotometric

Whole blood/plasma HPLC-micromethod

Minerals and trace elements

Total Ca Plasma Colorimetric

Ionized Ca Plasma Selective electrode

Bone density Metacarpal indices Radiographic or dual-photon absorptiometry

Hydroxyproline Urine Colorimetric

Osteocalcin Serum Radioimmunoassay

Phosphorus Plasma or serum Spectrophotometric

Magnesium Serum or urine AAS

Serum Colorimetric

Ferritin Serum or plasma ELISA

RIA

IRMA

Iron Serum Spectrophotometric or AAS

Iron binding capacity Plasma or serum Colorimetric or radioactive

Protoporphyrin Erythrocytes Hemofluorometer

Fluorometric

Transferrin receptor Serum ELISA

Hemoglobin Blood Spectrophotometric or electronic counter

Hematocrit Blood Special centrifuge or electronic counter

Zinc Plasma or serum AAS

Leukocyte and leukocyte subsets AAS

Hair AAS

Taste acuity Threshold of test solutions

Copper Plasma or serum AAS or colorimetric

Ceruloplasmin Serum Spectrophotometric

Table 1 Continued

Continued

NUTRITIONAL ASSESSMENT/Importance of Measuring Nutritional Status 4179

same country or even of the same area, are collected.

This is not necessary for nutritional surveillance, for

which international references should be used.

0034 In addition, for the interpretation of data, con-

founding factors must be taken into consideration,

because they can alter the status and needs of some

nutrients. Good examples are smoking habits, alco-

hol intake, drug use and abuse, physical activity, and

consumption of toxic and antinutritive substances.

Use of Data

0035 The main use of nutritional status data is to assess

prevalence of malnutrition or deficiency in cross-

sectional studies and/or the study of the association

of malnutrition and its determinants in longitudinal

studies.

0036 An additional and important use of these data is for

surveillance or intervention programs. In this case the

data collection is often limited to the most relevant

indicators of major risk for the population surveyed

or the most vulnerable groups inside the population,

such as pregnant and lactating women, children, ado-

lescents, and the elderly. Nutrition-related risk factors

of chronic disease have recently been included in the

surveillance programs.

0037 The assessment of nutritional status of single pa-

tients can be used for predicting outcome, and for

establishing the need for, and monitoring the effect

of, nutritional support. In this case the measurement

of special biochemical markers of stress is highly

recommended.

Limitations of Data

0038Most of the biochemical indices mentioned in Table 1

are static indices (measures of the concentration of a

nutrient or its metabolites in a suitable biochemical

matrix) that do not give information on the functions

of the body. It would be desirable to measure organ

functions instead (they depend on the adequate avail-

ability of a nutrient or the response to the regulatory

process to maintain body stores). However, few sen-

sitive and reliable functional tests are available and

some of them are not specific for a single nutrient or

not easily applicable in the field.

0039Other limiting factors are intraindividual variance

and the lack of harmonization and standardization of

methodology. As yet, there are no official methods for

nutritional status assessment and there are too few

quality controls and interlaboratory comparisons.

There are currently few reference laboratories and

official standards from international or national

agencies. This makes comparison of data from differ-

ent studies difficult.

0040The reliability and validity of the methods used are

not always assessed. It is true that in some cases

assessment of true validity is almost impossible. But

concurrent or other types of validity are available.

This is an area that needs much more consideration.

0041Also important factors which are not always asses-

sed in nutritional epidemiology include sensitivity,

specificity, and variability of indicators. The sensitiv-

ity can be diagnostic (the capacity to detect the earli-

est stages of deficiency) and biochemical (reflecting

Item Assessed variable Method or apparatus

Superoxide dismutase Erythrocytes Spectrophotometric

Selenium Whole blood or plasma AAS or fluorometric

Glutathione peroxidase Erythrocytes, plasma or platelets Spectrophotometric

Chromium Serum Graphite furnace AAS

Manganese Plasma or serum Graphite furnace AAS

Immunocompetence

Lymphocyte count Blood Blood cell counter

Delayed cutaneous hypersensitivity Skin Recall antigens (multitest)

Complement C

and factor B Serum Radial immunodiffusion or nephelometric

Secretory IgA Saliva or tears Radial immunodiffusion or nephelometric

T-lymphocyte and subset percentage Blood mononuclear cells Fluorescence microscopy or cytofluorometric

Lymphocyte proliferation Blood mononuclear cells Cell harvester and b-counter

Clinical examination Various forms

Psychometrics Various tests

Percent body fat can be computed if population-specific equations are available.

Micromethod available.

Measurable simultaneously.

Micromethod and automation available.

Short-term status.

TSF, triceps skinfold; HPLC, high-performance liquid chromatography; IGF-1, insulin-like growth factor 1; RIA, radioimmunoassay; GC-MS,

gas chromatography–mass spectrometry; AAS, atomic absorption spectrometry; ELISA, enzyme-linked immunosorbent assay; IRMA,

immunoradiometric assay.

Table 1 Continued

4180 NUTRITIONAL ASSESSMENT/Importance of Measuring Nutritional Status

every stage of the deficiency). The variability can be

analytical (instrumental, preinstrumental), and bio-

logical (intraindividual, interindividual). The above

items are limiting factors in data interpretation.

See also: Dietary Surveys: Measurement of Food Intake;

Surveys of National Food Intake; Surveys of Food Intakes

in Groups and Individuals; Epidemiology; Malnutrition:

The Problem of Malnutrition; Malnutrition in Developed

Countries

Further Reading

Fidanza F (ed.) (1991) Nutritional Status Assessment – A

Manual for Population Studies. London: Chapman &

Hall.

Gibson RS (1990) Principle of Nutritional Assessment.

New York, NY: Oxford University Press.

Jelliffe DB and Jelliffe EFP (1989) Community Nutritional

Assessment. Oxford: Oxford University Press.

Kinney JM, Jeejeeboy KN, Hill GL and Owens OE (eds)

(1988) Nutrition and Metabolism in Patient Care. Phila-

delphia: Saunders.

Sauberlich HE (1999) Laboratory Tests for the Assessment

of Nutritional Status, 2nd edn. Boca Raton: CRC Press.

van den Berg H, Heseker H, Lamand M et al. (1993) Flair

concerted action no 10 status paper. International Jour-

nal of Vitamin and Nutrition Research 63: 247–316.

Wang ZM, Pierson RN and Heymsfield SB (1992) The five

level model: a new approach to organizing body com-

position research. American Journal of Clinical Nutri-

tion 56: 19–28.

WHO Expert Committee Report (1995) Physical Status:

The Use and Interpretation of Anthropometry. Geneva:

World Health Organization.

Anthropometry and Clinical

Examination

J R Lustig and B J G Strauss, Monash Medical

Centre, Clayton, Victoria, Australia

Introduction

0001 A quick glance at a person will provide a gross esti-

mation of nutritional status. Irrespective of training,

we are all able to make these assessments: a Sumo

wrestler is obese or overnourished, whilst a terminal

AIDS patient is wasted and suffers from undernutri-

tion. These assessments, however, are merely qualita-

tive and contribute little to quantifying the nature and

extent of these observations.

0002Anthropometry comprises techniques that readily

contribute to a more in-depth understanding of body

composition and nutritional status, allowing the

quantification of observations and the observation

of changes with time.

0003Anthropometric methods are based on a model of

body composition that consists of two distinct com-

partments: fat mass and fat-free mass (see Table 1).

This two-compartment model of body composition

defines the fat-free mass as a compartment consisting

of body cells including skeletal muscle, extracellular

water, the skeleton, and connective tissue, with the fat

compartment consisting of the adipose tissue stores of

the body, which has a very small cellular and water

component. Anthropometric measurements can

indirectly assess these two body compartments and

thus provide an index of nutritional status. Alter-

ations in body fat content generally are sensitive to

changes in energy balance. Chronic malnutrition is

reflected in changes to the protein stores found pre-

dominantly in skeletal muscle in the body.

0004Anthropometric techniques are rapid, portable,

noninvasive, and inexpensive. The equipment re-

quired includes a tape measure, stadiometer (for

measuring height), standardized weight scales, and

skin-fold calipers. These techniques are frequently

used in nutritional assessment and for monitoring

changes in a diverse range of clinical settings. Such

settings include tertiary referral centres, isolated

rural practices, and population-based epidemiological

studies. They are also used in gymnasia, infant wel-

fare centers, schools, insurance assessments, sports

clubs, and so on.

Anthropometric Assessment of Fat Mass

Body Mass Index (BMI)

BMI ¼

weight ðkgÞ

height ðm

0005Weight should be measured using standardized, good-

quality weighing scales. The weight range of the

scales should be known and should be appropriate

for the subjects being weighed. This is particularly

tbl0001Table 1 Two-compartment model of body composition

Compartment Anthropometric technique used

Fat mass/distribution Body mass index

Skinfold thicknesses

Abdominal circumference

Abdominal:gluteal ratio

Fat-free mass Midarm circumference

Midarm muscle circumference

Midarm muscle area

NUTRITIONAL ASSESSMENT/Anthropometry and Clinical Examination 4181

important for the larger weights. Many instruments

are not designed for weighing above 120 kg and are

inaccurate when approaching higher weights.

0006 Height is measured in the standing position using a

stadiometer. Alternatively, a measuring stick attached

to a vertical surface with some form of right-angled

headboard can be used. Portable versions have been

developed for field work. Shoes and socks should be

removed and clothing kept to a minimum in order to

allow assessment of posture. The subject should stand

upright with the feet, buttocks, and shoulder blades in

contact with the vertical surface or stadiometer. The

head is positioned so that the Frankfurt plane (the line

between the top of the pinna and the outer canthus of

the eye) is horizontal. The subject is asked to take a

deep breath, and the movable headboard is lowered

until it is touching the crown of the head. The height

is measured at maximum inspiration with the exam-

iner’s eyes level with the headboard to avoid any

errors of parallax. The measurement is read to the

nearest millimeter, the lower value being used if the

level falls between two values.

0007 Because of kyphosis or other postural problems, or,

in the case of a patient being confined to bed, knee

height has been used as a surrogate for estimating

stature, and regression formulae have been developed

to estimate height from knee height.

0008 The BMI or Quetelet’s index is the most commonly

used weight/height ratio in adult populations. The

BMI has a reasonable correlation with relative fat

mass, as measured by body-density techniques. The

correlation between BMI and relative fat mass, as

measured by underwater weighing, was found to be

0.82 for a sample of women and 0.70 for a male

sample. Another limitation on the usefulness of BMI

in predicting body fatness in a given individual relates

to the weight nominator. As weight is influenced by

muscle, bone, and water as well as by fat, an individ-

ual with a well-developed musculo-skeletal system

relative to height may have a BMI in the obese range

but will not be overfat. BMI should thus be con-

sidered in the light of an individual’s physical activity

level.

0009 Classifications of BMI have been developed, and

these define relative levels of adiposity (see Table 2).

Such a classification is based on surveys of Caucasian

populations and may not apply to other ethnic

groups. In addition, there is a good correlation be-

tween BMI and morbidity and mortality from obesity,

e.g., heart failure, osteoarthritis, and hypertension.

0010 The BMI can also be used as an index of wasting.

Population studies have shown an increase in morbid-

ity and mortality, and alterations in immune function

as the BMI falls below 18.5, irrespective of the type

of population, from undernourished groups, to those

with clinical illnesses such as malignancies. The

WHO has graded wasting on the basis of the BMI

into mild (BMI, 18.5), moderate (BMI < 17.5) and

severe (BMI < 16.5).

Abdominal:Gluteal Circumference Ratio

0011The ratio of the abdominal circumference to the max-

imal gluteal circumference defines the distribution of

adipose tissue in the body. The waist is measured with

the subject standing erect and undressed. The abdom-

inal circumference is measured at the midpoint of

the line between the rib or costal margin and the iliac

crest in the midaxillary line. The maximal gluteal

(buttock) circumference is also measured with the

subject standing erect. It is important to define the

sites measured and maintain consistency in these sites

in order to compare sets of data.

0012A waist/hip ratio > 0.95 in males and > 0.85 females

is consistent with abdominal obesity.

0013Abdominal fat distribution is associated with a

range of adverse health consequences, including

an increased risk of cardiovascular and cerebro-

vascular disease, impaired glucose tolerance, and

hypertriglyceridemia, even when the BMI is in the

‘healthy’ range.

Skin-fold Thicknesses

0014Estimation of body fat content from skin-fold thick-

nesses assumes that measurements of subcutaneous

fat represent total body fat. This assumption is not

strictly true, as the thickness of subcutaneous fat does

not necessarily reflect a constant proportion of total

body fat. In addition, there are marked variations

in the distribution of subcutaneous fat depending on

age, sex, and race. None the less, this method pro-

vides useful information and is in routine use. Skin-

fold thickness measurements may be taken at single

or multiple sites. There is no universal agreement as to

which skin-fold best represents total body fat. How-

ever, the triceps skin-fold is most frequently selected

for a single-site assessment of body fat.

tbl0002Table 2 Classifications for body mass index

Bodymassindex

(kg m

2

)

Healthassociation

<16.0 Severe protein-energy malnutrition

16.0–16.9 Moderate protein-energy malnutrition

17.0–18.5 Mild protein-energy malnutrition

20.0–24.9 Apparently healthy, with low health risk

25.0–29.9 Overweight, with increased health risk

30.0–39.9 Obesity, increased macrovascular disease

and diabetes mellitus

>40.0 ‘Super obesity’ with major morbidity

4182 NUTRITIONAL ASSESSMENT/Anthropometry and Clinical Examination

0015 The measurement of the triceps skin-fold is taken

at the midpoint of the upper arm. With the elbow

bent to 90% the midpoint is located half-way be-

tween the acromium process of the shoulder and the

olecranon process of the ulna. This point should

be marked. The arm is then extended and allowed

to hang loosely by the side. Using the thumb and

forefinger, the skin-fold is grasped just above the

midarm point. The calipers are applied at right angles

to the skin at the midarm point and 1 cm in from

the surface. The fold should remain held whilst the

measurement is taken. Multiple skin-fold sites can

be assessed and usually include both limb and

trunk sites.

0016 Body density can be estimated from skin-fold meas-

urements. Using regression equations such as Durnin

and Womersley’s, skin-folds, sex, and age are used to

derive body fat and fat-free mass. For example, for

males aged 30–39 years:

0017 D (gm

3

) ¼1.1422 (0 0544 log

(Skinfold

sum [mm])), where D ¼density; skinfold sum ¼

biceps þtriceps þsubscapular þiliac.

0018 Percentage body fat or relative fat mass can then

be calculated. Several equations have been de-

rived. The Siri equation assumes that the density

of fat is 0.900 g cm

3

and that the density of

the fat-free mass is 1.100 g cm

3

: % fat ¼[(4.95/

D) 4.50] 100.

0019 Total body fat is derived as follows: total body fat

(kg) ¼[body weight (kg) % body fat]/100.

0020 Fat-free mass (kg) ¼body weight (kg) body fat

(kg).

Both the skill of the operator and the character of

the subcutaneous fat in an individual can influence the

precision of skin-fold measurements. In general, the

error of this method is approximately 5%. Depending

on the equation used and the population studied, this

may range from 3 to 9% body fat mass. Durnin and

Womersley derived values for calculation of fat mass

for all age groups in both men and women.

Anthropometric Assessment of Fat-Free

Mass

Mid-arm Circumference

0021 The upper arm contains both muscle and subcutane-

ous fat, so that measurement of the circumference

of the midupper arm may be used as an index of

nutritional status. In underdeveloped countries

where the population is often malnourished and

with little fat reserves, a change in this measurement

can reflect total body protein stores. Serial measure-

ment of the upper-arm circumference may be used to

monitor nutritional intervention. Measurement of

this circumference is described in the section on

skin-fold thicknesses.

Midarm Muscle Circumference

0022In practice, midarm muscle circumference is used in

preference to midarm circumference as a measure-

ment which reflects total body protein stores. The

upper-arm circumference comprises central bone sur-

rounded by a layer of skeletal muscle and subcutane-

ous fat. The midarm muscle circumference, derived

from the midarm circumference and the triceps skin-

fold thickness, takes into account an assessment of

both fat and protein stores.

0023Small changes in muscle mass may not be detected

by this technique. In addition, individual variations

in the diameter of the humerus are not taken into

account in this calculation. Midarm muscle circum-

ference is derived using the following equation:

Midarm muscle circumference ¼

midupper arm circumference ðp  TSFÞ,

where TSF ¼triceps skinfold thickness (in cm).

Midarm Muscle Area

0024Midarm muscle area provides a higher correlation

with body protein stores than does either of the mid-

arm circumferences. Because it takes into account a

two-dimensional assessment, it reflects more accur-

ately small changes in muscle mass. None the less, one

appraisal of the equation suggests that it may under-

estimate significantly the degree of muscle wasting.

Midarm muscle area may be calculated using the

following equation:

arm muscle area ¼½C ðp  TSFÞ

=4p,

where C ¼midupper arm circumference, and TSF

triceps skinfold thickness (in cm).

0025The coefficient of variation for the measurement of

midarm muscle area has been estimated as approxi-

mately 7% when made by trained operators. This is

therefore not a sensitive enough method by which to

detect small changes in muscle mass.

Conclusions

0026Anthropometry provides a rapid methodology for the

indirect quantification of fat and fat-free mass and,

thus, the body compositional aspects of nutritional

status. The techniques require little in the way of

equipment and are readily portable and inexpensive.

Although they are insensitive to small changes in

nutritional status, they have a useful role to play in

assessment of nutritional status and for monitoring

NUTRITIONAL ASSESSMENT/Anthropometry and Clinical Examination 4183