Waist Circumference

Placement, tightness and type of measuring tape

Waist circumference

1. The WHO STEP wise Approach to Surveillance (STEPS) provides a simple standardized method for collecting, analysing and disseminating data in WHO Member countries. The WHO STEPS protocol for measuring waist circumference instructs that the measurement be made at the approximate midpoint between the lower margin of the last palpable rib andthe top of the iliac crest (WHO, 2008b).
2. The United States (US) National Institutes of Health (NIH) protocol provided in the NIH Practical guide to obesity (NHLBI Obesity Education Initiative, 2000) and the protocol used in the US National Health and Nutrition Examination Survey (NHANES) III (Westat Inc, 1998) indicate that the waist circumference measurement
   should be made at the top of the iliac crest.
   The NIH also provided a protocol for the measurement of waist circumference for the Multi‐Ethnic Study of Atherosclerosis (MESA) study. This protocol indicates that the waist measurement should be made at the level of the umbilicus or navel. However, published reports indicate that measurements of waist circumference made at the level of the umbilicus may underestimate the true waist circumference (Croft et al., 1995).
3. Some studies have assessed the waist circumference at the point of the minimal waist (Ross et al., 2008).

Tightness and type of tape
The accuracy of waist and hip circumference measurements depends on the tightness of the measuring tape, and on its correct positioning (i.e. parallel to the floor at the level at which the measurement is made).

1. The WHO STEPS protocol states that, for both waist and hip, the tape should be snug around the body, but not pulled so tight that it is constricting (WHO, 2008b). The protocol also recommends the use of a stretch‐resistant tape that
   provides a constant 100 g of tension through the use of a special indicator buckle; use of this type of tape reduces differences in tightness.
2. Both the protocol described in NIH Practical guide to obesity (NHLBI Obesity Education Initiative, 2000) and the NHANES III protocol (Westat Inc, 1998) recommend that the measurements be made with the tape held snugly, but not constricting, and at a level parallel to the floor.

Subject posture and other factors

1. Posture of the subjects during the measurement
   The posture of the subject at the time the measurement is taken influences the accuracy of the measurement. Thus, the WHO STEPS protocol recommends that the subject stands with arms at the sides, feet positioned close together, and weight evenly distributed across the feet (WHO, 2008b). The NHANES III protocol recommends that the subject be standing erect, with the body weight evenly distributed (Westat Inc, 1998).
2. Phase of respiration at the exact point of measurement
   The phase of respiration determines the extent of fullness of the lungs and the position of the diaphragm at the time of measurement; it also influences the accuracy of the waist circumference. The WHO STEPS protocol suggests that the waist circumference should be measured at the end of a normal expiration, when the lungs are at their functional residual capacity (WHO, 2008b). The NHANES III protocol states that the waist circumference should be measured at minimal expiration (Westat Inc, 1998).
3. Abdominal tension at the point of measurement
   The tension of the abdominal wall influences the accuracy of the waist circumference measurement. Lowering the tension of the abdominal wall increases waist circumference, whereas increasing the tension (by sucking in) reduces waist circumference. Many individuals unconsciously react to waist measurements by sucking in the abdominal wall; hence, a relaxed posture is best for taking waist measurements. The WHO STEPS protocol recommends advising the subject to relax and take a few deep, natural breaths before the actual measurement is made, to minimize the inward pull of the abdominal contents during the waist measurement (WHO, 2008b).
4. Influence of stomach contents at time of measurement
   The amount of water, food or gas in the gastrointestinal tract will affect the accuracy of the waist measurement. Gibson (1990) suggests that a waist measurement be made after the subject has fasted overnight or is in a fasted state, to reduce this effect. None of the protocols evaluated address this issue, perhaps because it would entail the subject being notified in advance of the measurement, and being present the morning after an overnight fast.

follow these three simple steps ……

Place the tape measure around your waist, at the halfway point between the bottom of your lowest rib & the top of your hip bone. If you have trouble finding this point, then lean to one side & see where the skin folds. This is the point where you can measure your waist.

Make sure it’s level & a snug fit, but not digging into your skin.

Breathe normally, & measure after you have breathed out.

What is a healthy measurement ?

Sex	­ Risk	Risk
Males	> 94 cm	>= 102 cm
	37 inch	40.1 inch
Females	>= 80 cm	>= 88 cm
	31.5 inch	34.6 inch