Recommendations of Major Authorities

• American Academy of Family Physicians --
• All patients should be measured for height and weight periodically.

• American College of Obstetricians and Gynecologists --
• Height and weight should be measured as part of periodic evaluation visits, which should occur yearly or as appropriate.

• Canadian Task Force on the Periodic Health Examination --
• There is insufficient evidence to recommend the inclusion or exclusion of height and weight measurement and BMI calculation in the periodic health examination, given the lack of long-term effectiveness of weight reduction therapy in the large majority of obese individuals. Weight reduction can be cautiously recommended in persons with obesity and coexistent diabetes, hypertension, or hyperlipidemia.

• US Department of Agriculture, US Department of Health and Human Services --
• Calculation of the ratio of waist circumference to hip circumference can be used, in addition toheight and weight measurements, to help evaluate body weight.

• US Preventive Services Task Force --
• All adults should receive periodic measurement of height and weight. The optimal frequency for measuring height and weight in adults is a matter of clinical discretion. There is insufficient evidence to recommend for or against determination of the waist/hip ratio (WHR) as a routine screening test for obesity.

Basics of Body Measurement Screening

• 1. To ensure accuracy, measure height while the patient is barefoot or in socks or stockings only. Make sure that the patient is standing as erect as possible, with feet flat on the floor. Height-measuring rods attached to scales should be regularly checked for accuracy, because they become inaccurate with use.

• 2. Use a balance beam or electronic scale (not a spring-type scale) to measure weight. The measurement will be most accurate if the patient is wearing minimal or no clothing. Calibrate scales on a regular basis.

• 3. Historically, the definition of "healthy" weight has been a subject of debate. Typically, two different methods have been used for evaluating weight: (1) comparison with the Metropolitan Life Insurance Tables, and (2) calculation of body mass index (BMI).

• Clinicians have been most accustomed to using height-weight tables. Early tables were adapted from those developed in 1959 by the Metropolitan Life Insurance Company and were based on weights associated with minimal mortality. Although these tables were widely circulated and used, they had significant limitations: they included subjective estimates of body frame size and were based on an insured population, which may not be representative of the overall US population.

• Today, most authorities endorse using BMI to evaluate healthy weight for adults. The formula for calculating BMI is:

Weight(kg)
Height(m)²

• Although authorities previously suggested that the ranges of "healthy" BMI and weight should increase with age, most authorities now do not believe that such age adjustments are valid. Table 29.1 presents an easy way to calculate an individual's BMI based on the person's height and weight.

Table

Table 29.1. Body Weights in Pounds According to Height and Body Mass Index *.

• In 1995, the US Departments of Agriculture and Health and Human Services published new healthy weight ranges for adult men and women in Dietary Guidelines for Americans (see Selected References). These ranges, proposed by an expert committee and adopted by the Departments, are based on an extensive review of the literature pertaining to weight-related risk of morbidity and mortality over a range of BMI values. The weight ranges are presented in Table 29.2 and Figure 29.1. Note that the higher weights apply to people with more muscle and bone.

Table

Table 29.2. Healthy Weight Ranges for Adult Men and Women.

Figure

Figure 29.1. Weight Chart for Adult Men and Women* . * The use of shading on the figure reflects the lack of consensus about exact cutoff points and emphasizes that disease risk varies with degree of overweight. Note: (more...)

• The upper boundary of healthy weight corresponds to a BMI of about 25, based on the significant increase in risk of mortality that occurs among persons with BMI values above this cutoff point. The lower boundary of healthy weight represents a BMI of 19, although whether a weight below this level is unhealthy remains unclear. BMI values above 28 to 29, the boundary between moderate and severe overweight, are associated with an increasingly higher risk of disease and death.

• 4. Research indicates that WHR or absolute weight circumference may be stronger predictors of mortality than are measures of general body adiposity. Determination of WHR is also useful for assessing patients, particularly those who have weight that is borderline-high and a personal or family medical history placing them at increased health risk. Determine the WHR by measuring the abdominal (waist) circumference and the hip circumference. Measure the abdominal circumference at the level of the umbilicus (or the level of greatest anterior extension of the abdomen) while the patient is standing. Determine the hip circumference by measuring the greatest circumference at the level of the buttocks. Obtain both measurements after a normal expiration by the patient and without indenting the skin. The formula for calculating WHR is:

• Abdominal Circumference
  Hip Circumference

• WHR values above 1.0 for men and above 0.8 for women are associated with an increased risk of diabetes, hypertension, heart disease, and stroke. An absolute waist circumference measurement greater than 100 cm is also associated with an increased disease risk. However, evidence suggests that WHR or waist circumference and disease risk may not have as strong an association in some minority populations.

• 5. Bioelectric impedance analysis (BIA), a new technique for quickly estimating body composition, is currently used in many different practice settings. In theory, this technique measures the electrical impedance, or resistance, to the flow of electricity, in the body. From this measurement, an estimate of total body water (TBW) is calculated. An estimate of fat-free mass and body fat (adiposity) can then be determined. However, no industry standards for BIA currently exist, and a person's body fat measurement may vary by as much as 10% of body weight depending on the technique, machinery, conditions, and equations used. Variables that can affect the measurements include body position, hydration status, consumption of foods and beverages, ambient air and skin temperature, recent physical activity, and conductance of the examining table. Only when these variables become controlled and standardized may BIA prove to be a quick, accurate, and noninvasive way to determine body fat.

Patient Resources

• Nutrition and Health: Dietary Guidelines for Americans. 4th ed. US Dept of Agriculture and US Dept of Health and Human Services, 1995. This material is available from the Consumer Information Center — 3C, Dept 514-X, Pueblo, CO 81009.

• Check Your Weight and Heart Disease I.Q. This information is available in both English and Spanish. National Heart, Lung, and Blood Institute Information Center, PO Box 30105, Bethesda, MD 20824-0105; (301)251-1222. Internet address: http://www.nhlbi.nih.gov/nhlbi/nhlbi.htm

• Weight Control: Losing Weight and Keeping It Off. American Academy of Family Physicians, 8880 Ward Parkway, Kansas City, MO 64114-2797; (800)944-0000. Internet address: http://www.aafp.org

• Bioelectric Impedance Analysis in Body Composition Measurement; Understanding Adult Obesity; Weight Cycling. The National Institute of Diabetes and Digestive and Kidney Disease, 1 WIN Way, Bethesda, MD 20892-3665; (800)946-8098.

Selected References

1. American Academy of Family Physicians. Summary of Policy Recommendations for Periodic Health Examination. Kansas City, Mo: American Academy of Family Physicians; 1997.
2. American College of Obstetricians and Gynecologists. Guidelines for Women's Health Care. Washington, DC: American College of Obstetricians and Gynecologists; 1996.
3. Bjorntorp P. Regional patterns of fat distribution. Ann Intern Med. . 1985; 103:994–995. [PubMed: 4062132]
4. Bray GA, Gray DS. Obesity: part 1 — pathogenesis. West J Med. . 1988; 149:429–441. [PMC free article: PMC1026489] [PubMed: 3067447]
5. Canadian Task Force on the Periodic Health Examination. Prevention of obesity in adults. In: The Canadian Guide to Clinical Preventive Health Care. Ottawa, Canada: Minister of Supply and Services; 1994: chap 48.
6. Federation of American Societies for Experimental Biology, Life Sciences Research Office. Third Report on Nutrition Monitoring in the United States. Washington, DC: US Government Printing Office; 1995.
7. Folsom AR, Kaye SA, Sellers TA, et al. Body fat distribution and 5-year risk of death in older women. JAMA. . 1993; 269:483–487. [PubMed: 8419667]
8. Hubert HB, Feinleib M, McNamara PM, Castelli WP. Obesity as an independent risk factor for cardiovascular disease: a 26-year follow-up of participants in the Framingham Heart Study. Circulation. . 1983; 67:968–977. [PubMed: 6219830]
9. Lissner L, Odell PM, D'Agostino RB, et al. Variability of body weight and health outcomes in the Framingham population. N Engl J Med. . 1991; 324:1839–1844. [PubMed: 2041550]
10. Lohman TG, Roche AF, Martorell R. Anthropometric Standardization Reference Manual. Champaign, Ill: Human Kinetics Books; 1988.
11. Manson JE, Stampfer MJ, Hennekens CH, Willet WC. Body weight and longevity: a reassessment. JAMA. . 1987; 257:353–358. [PubMed: 3795418]
12. National Academy of Sciences, Committee on Diet and Health, Food and Nutrition Board, Commission on Life Sciences, National Research Council. Diet and Health: Implications for Reducing Chronic Disease Risk.Washington, DC: National Academy Press; 1989:564-565.
13. National Institutes of Health. National Institutes of Health Consensus Development Conference Statement: health implications of obesity. Ann Intern Med. . 1985; 103:1073–1077. [PubMed: 4062128]
14. National Institutes of Health. Bioelectric Impedance Analysis in Body Composition Measurement: Technology Assessment Conference Statement. Bethesda, Md.: National Institutes of Health; 1994.
15. Rowland ML. A nomogram for computing body mass index. Dietetic Currents. . 1989; 16:5–12.
16. Simpoulos AP, Van Itallie TB. Body weight, health and longevity. Ann Intern Med. . 1984; 100:285–295. [PubMed: 6362514]
17. US Department of Agriculture, Agricultural Research Service; Dietary Guidelines Advisory Committee, 1995. Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 1995. Washington, DC: US Department of Agriculture; 1995.
18. US Department of Agriculture, US Department of Health and Human Services. Nutrition and Your Health: Dietary Guidelines for Americans. Washington DC: US Government Printing Office; 1995. Home and Garden Bulletin 232.
19. US Preventive Services Task Force. Screening for obesity.In: Guide to Clinical Preventive Services. 2nd ed. Washington, DC: US Department of Health and Human Services; 1996: chap 21.
20. Van Itallie TB. Health implications of overweight and obesity in the United States. Ann Intern Med. . 1985; 103:983–988. [PubMed: 4062130]