Need to lose weight? Lets measure fat by folding skin! One of the more popular methods, Durnin-Womersley, involves taking skin fold measures on the bicep, tricep, subscapular (shoulder blade) and suprailiac (waist). The measures (in millimetres) are put into a calculation to estimate body density. A second calculation then estimates body fat based on the body density. The general consensus for acceptable body fat is 18 – 25% for men and 25 – 31% for women. Based on Durnin-Womersley:
If you are a male over 50 years the total of the skin fold measurements should not exceed 45 mm.
If you are a male 30 – 50 years the total of the skin fold measurements should not exceed 60 mm.
If you are a female over 50 years the total of the skin fold measurements should not exceed 42 mm.
If you are a female 30 – 50 years the total of the skin fold measurements should not exceed 55 mm.
Athletes seek lower body fat and the ideal percentage body fat varies between sports. Some push the boundaries of what is safe and healthy at the lean end of the scales. We just need to get into the acceptable zone.
Note: Another commonly used skin fold method is the Jackson-Pollock method based on seven skin fold measurements.
How do you shape up?
regards, Keith
Need to lose weight? How massive is your index? The Body Mass Index (BMI) is a commonly used indicator of total body fat. It is certainly supported by major health organisations. As it is based on the relationship between your height and weight its simplicity is both a strength and a weakness. It is a strength because it is easy to calculate (and BMI calculators are readily available on the internet). It is a weakness in that it can over-estimate body fat for athletes and those of muscular build and under-estimate for the elderly and those who have lost muscle mass.
I wonder if some of the criticism of the Index is based on denial. When I was at my heaviest I was borderline obese according to the index. I found this hard to accept. Me. Obese. Never. A bit overweight maybe. Although I didn’t set my goal weight with the BMI in mind it turns out my goal weight was equal to a BMI of 23, comfortably inside the Normal range. A score of 23 was easily achievable for someone of my build.
BMI Table: BMI categories as per the US Department of Health and Human Services
|
|
BMI
|
| Underweight |
Below 18.5
|
| Normal |
18.5 – 24.9
|
| Overweight |
25.0 – 29.9
|
| Obesity |
30.0 and Above
|
Even if you are suspicious of the above table tracking your BMI as you lose weight can be motivational. You may wish to use BMI scores as a set of short term goals to track progress to your goal weight.
While I use any of the many BMI calculators on the internet you can also use the following formulas:
BMI Metric Calculation
BMI = weight in kilograms divided by height in metres squared = kg / m²
BMI Imperial Calculation
BMI = weight in pounds x 703 divided by height in inches squared
= (lbs x 703) / inches²
All the best, Keith
