Excerpt from Chapter 3: BODY WEIGHT ASSESSMENT **
People people want to know what they should weigh. But body weight, as measured on a bathroom scale, can actually be misleading and certainly does not tell the whole story. There are a number of techniques that can be used to determine what your client should weigh. In this chapter we will cover the familiar Weight versus Height table, and then introduce a new BMI-based Weight versus Height table, a new Body-Fat Percentage table and Maximum and Optimum Waist Size tables - tables not found in any other book.
BMI-Based Weight vs Height Table
A more convenient way to use BMI is the New BMI-Based Weight vs. Height Chart shown in Table 3.4, where the underweight category corresponds to BMI = 18.5 or less, normal weight is for BMI = 18.6 to 24.9, overweight is for BMI = 25.0 to 29.9, obese is for BMI = 30.0 to 39.9 and extremely obese is for BMI = 40 or more.
Example 3.1: Determine "Normal" weight for a woman 165 cm tall who weighs 70 kilos.
Scan the far left of the Table 3.4 and locate her 165 cm height. From this number run your finger horizontally (to the right) until it intersects the vertical column headed by "Normal Weight." The numbers at the intersection indicate she should weigh between 51 and 68 kg, that is what she should weigh for her BMI to be between 18.6 and 24.9. So, according to Table 3.4 at 70 kg she is slightly overweight.
Waist to Hip Ratio
The waist-to-hip ratio is often viewed as an indicator of health and the risk of developing serious health conditions. It is also used as a measurement of obesity, which in turn is a possible indicator of other serious health conditions.
Measurement: The waist is measured at the smallest circumference of the natural waist, usually just above the belly button. If the waist is convex rather than concave, such as is the case in pregnancy and obesity, the waist should be measured at a horizontal level 2.5 cm above the navel. Hip circumference is measured at the widest part of the buttocks or hip.
The National Institute of Diabetes, Digestive and Kidney Diseases states that women with waist-to-hip ratios of more than 0.8 are at increased health risk. Moreover, The Centers for Disease Control and Prevention (CDC) has found that women with a ratio less than 0.8 are considered safe. And waist-to-hip ratios of 0.7 for women correlate strongly with general health and fertility. Women within the 0.7 range have optimal levels of estrogen and are less susceptible to major diseases such as diabetes, cardiovascular disorders and ovarian cancers.
Maximum Waist Size
The waist size beyond which a woman has increased health risk is referred to as her maximum waist size. To determine maximum waist size, Dr Antonetti inserted into the U.S. Navy body-girth correlation equation a maximum waist-to-hip ratio of 0.8 and a maximum age-adjusted body fat percentage from Table 3.5. (For example, for women 20 to 40 years old he used 33 percent.) He then solved for the maximum waist size as a function of neck size and height. The unique resulting equation is presented in tabular form in table 3.7 (for women 20 to 40), Table 3.8 (for women 41 to 60) and Table 3.9 (for women 61 to 80), on pages 28 to 30.
Example 3.4: Determine the maximum waist size for a 27 year-old woman who is 158 cm tall and has a 35 cm neck circumference.
Enter the left column of Table 3.8 at a height of 158 cm. From this number run your finger horizontally (to the right) until it intersects the vertical column headed by her 35 cm neck size. The number at the intersection is her Maximum Waist Size, which is 80 cm.