The Body Mass Index (BMI), a measure of weight in relation to height, is commonly used for classifying overweight and obesity.
The risks of cardiovascular disease and type 2 diabetes tend to increase on a continuum with increasing BMI, but for practical purposes a person with a BMI of over 25 is considered overweight, while someone with a BMI of over 30 is obese.
But one size does not fit all. In women, a BMI as low as 21 may be associated with the greatest protection from coronary heart disease death.
The BMI for observed risk in different Asian populations varies from 22 to 25 kg/m2. Therefore, dieticians, nutritionists and weight loss experts believe that other methods should also be used to evaluate a person’s overall health risk and the associated grade of obesity.
Alternatives to Body Mass Index :
There are two main and common alternatives to Body Mass Index.
1. Waist-Hip Ratio (Pears” vs. “Apples”) :
Health care providers are concerned not only with how much fat a person has, but also where the fat is located on the body.
Women typically collect fat in their hips and buttocks, giving them a “pear” shape. Men usually build up fat around their bellies, giving them more of an “apple” shape.
Of course some men are pear-shaped and some women become apple-shaped, especially after menopause.
If you carry fat mainly around your waist, you are more likely to develop obesity-related health problems.
Women with a waist measurement of more than 35 inches or men with a waist measurement of more than 40 inches have a higher health risk because of their fat distribution.
2. Waist circumference :
Circumference is the perimeter of, or the distance around a circle. So waist circumference is a measure of the distance around the abdomen.
Waist circumference is one of the most practical tools to assess abdominal fat for chronic disease risk and during weight loss treatment.
A high waist circumference or a greater level of abdominal fat is associated with an increased risk for type 2 diabetes, high cholesterol, high blood pressure and heart disease.
According to the United States Department of Health and Human Services the following individuals are at increased risk for developing chronic diseases:
• Women with a waist circumference of more than 35 inches.
• Men with a waist circumference of more than 40 inches.
However, lower thresholds for waist circumference have been recommended for Asian populations by the World Health Organization due to recent research findings.
Therefore, those at increased risk for developing chronic disease include:
• Asian women with a waist circumference of more than 31 inches.
• Asian men with a waist circumference of more than 35 inches.
To measure waist circumference locate the top of the hip bone. Place the tape measure evenly around the bare abdomen at the level of this bone. Read the tape measure and record the waist circumference in inches. Ensure that the tape is sung but does not push tightly into the skin and you measure waist circumference after breathing out normally.
Is waist circumference better indicator than BMI ?
Waist circumference may be a better indicator of health risk than BMI alone, especially when used in combination with BMI.
Waist circumference is particularly useful for individuals with a BMI of 25-34.9. For individuals with a BMI > than 35, waist circumference adds little predictive power on the disease risk classification of BMI.
Studies have shown that the distribution of body fat is associated with an increased prevalence of diabetes, hypertension, high cholesterol and cardiovascular disease.
Generally, the association between health risks and body fat distribution is as follows:
• Least risk – slim (no pot belly)
• Moderate risk – overweight with no pot belly
• Moderate to high risk – slim with pot belly
• High risk – overweight with pot belly.
Waist circumference and health risks :
Waist circumference can be used to indicate health risk.
For men :
• 94cm or more – increased risk
• 102cm or more – substantially increased risk.
For women :
• 80cm or more – increased risk
• 88cm or more – substantially increased risk.
Conclusion :
It is crystal clear from the above discussion that no single measure including BMI is 100 accurate in determining the exact health risk due to your body weight.
You should, therefore, reply on , multiple methods such as BMI, wait to hip ratio and waist circumference to evaluate such risks and their link with your body weight and body fat.
Tags:
General