Ideal Body Weight – Where am I?

When talking about body image, rarely people (especially women) satisfy with their body. Some of them think they’re too thin, while others (mostly) think they’re too fat. Before taking any strict diet or extreme exercise, it will be wise if we ‘know where we are’. There are some assessment methods we can use to find it out.

According to NIH (National Institutes of Health, USA), assessment of weight & height risk involves using 3 key measures:

1) BMI (Body Mass Index) or Quatelet Index (W/H²)àin which W is weight in kg & H is height in meters. The higher your BMI, the higher your risk for certain diseases (such as: heart disease, high blood pressure, type-2 diabetes, gallstones, breathing problem & certain cancers. The BMI scores means the following:

BMI Scores	Classification
<18.5	Underweight
18.5 – 24.9	Normal
25.0-29.9	Overweight
≥30	Obesity

2) Waist circumference à Waist circumference over 40 inches (±100 cm) in men & over 35 inches (±90 cm) in women can increase the risk of heart disease & type-2 diabetes.The ideal one is less than 90 cm for men & less than 80 cm for women.

3) Risk factors for diseases & conditions associated with obesity.

The more preferred method is BMI and waist circumference. While waist to hip ratio is now seldom used (Mahan & Stump, 2004). Although BMI can be used for most men & women, it also has some limitation. It may overestimate body fat (in person who has muscular build such as athlete) or underestimate body fat (in person who lost muscle such as elderly). It also cannot be used for children or pregnant women.

Regarding body fat composition, there are also several methods available to measure it. You can see the comparison in the table below:

Method	How to measure	Upside	Downside
Skin fold caliper	By pinching your fat with your fingers then measuring the thickness with body fat caliper	Accurate, dependable & repeatable	Variability of measurement, requires skilled pro to measure & can be less accurate for overweight people
BIA (Bioelectric Impedance Analysis)	Determines the electrical impedance (muscle has higher water content & more conductive than fat)	Very easy to administer & inexpensive	Questionable accuracy & depends on hydration level
Anthropometric	Uses body circumference to estimate body fat percentage (waist, neck & height for men, hips, neck & height for women)	Easy to administer & cheap	Questionable accuracy, the least accurate method
Hydrostatic Weighing	Requires to be submerged in a specialized tank of water, takes about 20-30 minutes. Person with higher % of fat free mass will weigh more in the water & have lower % of body fat.	Very accurate, considered gold standard	Impractical, expensive & not repeatable
DEXA Scan	Uses a body scanner with low dose x-rays, takes about 10-20 minutes	Very accurate	Expensive & not repeatable

After measuring your fat composition, you can use ideal body fat percentage chart to know ‘where you are’. One of the most commonly used body fat charts is from ACE (American Council on Exercise) as follows:

Description	Women	Men
Essential fat*	10-13%	2-5%
Athletes	14-20%	6-13%
Fitness	21-24%	14-17%
Average	25-31%	18-24%
Obese	32%+	25%+

*see glossary

In conclusion, you can feel satisfy with your body as long as you are in ‘normal/ideal category’ (for BMI & waist circumference) & ‘average-fitness-athletes’ (for body fat composition). Don’t forget to maintain your fitness with healthy diet & regular physical activity. If you’re falls into other category, then it’s time to set up your goal & work out more. Most importantly is to get healthier, not only slimmer.