Obesity affects not only our physical appearance but also our health. The normal ranges of body fat percentage are about 12% - 19% in men and 25% - 32% in women. Obesity results from abnormal or excessive body fat accumulation. Obesity is recognised as a disease by the World Health Organization (WHO) and may be accompanied by a wide range of chronic diseases.
Am I Obese?
To diagnose obesity, we have to determine the amount of fat in our body. Body fat can be measured by hydrostatic weighing, skinfold test and magnetic resonance imaging. However, these methods are complicated and are not routinely used in clinical settings.
1. Body Fat Percentage
Overweight and obesity are defined as abnormal or excessive body fat accumulation. The normal range of our body fat storage depends on our gender and age:
*Percentage of body fat cutoffs by sex, age, and race-ethnicity in the US adult population from NHANES 1999-2004. Heo M1, Faith MS, Pietrobelli A. Heymsfield SB. AM J Clin Nutr. 2012 Mar;95(3):594-602. doi: 10.3945/ajcn.111.025171.Epub 2012 Feb 1.
2. Body mass index
Body mass index (BMI) is most commonly used to assess body fat mass. Clinical research showed a strong correlation between BMI and body fat mass as measured by magnetic resonance imaging.
Body mass index is calculated using the following formula:
Body Mass Index (BMI) = Body Weight (kg) ÷ Body Height (m) ÷ Body Height (m)
According to the WHO Asia-Pacific guideline (2000), adult BMI can be categorised as follow:
Body Mass Index
Underweight
Normal
Overweight
Obese I
Obese II
BMI (kg/m2)
<18.5
18.5-22.9
23-24.9
25-29.9
≥30.0
3. Waist circumference
Researches have indicated that in addition to total body fat mass, body fat distribution also affects our health. Abdominal fat accumulation, also termed “central obesity”, is particularly harmful. Waist circumference is a good marker for central obesity. According to the WHO Asia-Pacific guideline in 2000, central obesity is defined as waist circumference greater than 90cm (35.5in) for men and 80cm (31.5in) for women.
