An obese person takes more energy to breathe because it takes his/ her heart to work harder to pump blood to the lungs and to the excess fat throughout the body. This increases workload and that may cause enlarged heart, lead to high blood pressure and life-threatening irregular heartbeats. Reduction of excess body fat through weight management program plays a vital role in maintaining good health and fighting diseases. Although a certain amount of fat is essential to our bodily functions because it controls our body temperature, insulates and cushions tissues and organs and it acts as an emergency source of energy but when it exceeds the required level it does more harm than good.

Body fats are called adipose tissue, body’s own way to store energy. There are two main types of body fats in our body. The major portion of body fats in human body is ‘white fat’ that stores energy. There is another type of fat, ‘brown fat’, mostly found in new born babies, that works as insulator, keeps the baby’s body warm. In adults, brown fat comprises a very little percentage of overall body fat.

Ways To calculate Body Fat Percentage

There are many ways to calculate body fat. One of the popular and most accepted method isSkin Fold Caliper which is discussed here.

Skin Fold Caliper

Skin Fold calipers are used in the measurement of Skin Fold thickness and the estimation of total body fat. This method measures your body fat percentage by pinching your body fat with your fingers in certain specific areas and then measuring the thickness of the pinched area with a body fat caliper. The reading in the caliper is given in millimeter. There is a standard chart that you have to read and compare with the measures you have found in the caliper. The measurement should be read and compare with the chart as per specific gender and ages. This method measures only one type of fat, subcutaneous adipose tissue (fat under the skin). The limitation of this method is that two different individual may have similar fat under the skin but may vary greatly in their body fat level. There are many types of caliper equipments such as Harpenden Caliper, Slim Guide Caliper, Fat Track Calipers, Lange Fat Caliper, Warrior Digital Body Mass Caliper, Pooya Caliper and many others which vary greatly in price, accuracy, reliability, quality, ease of use and jaw pressures and surface areas.

The percent of fat is determined by two steps under this method. Firstly, the body density is estimated and then body density is used to estimate percent of fat. There are several Skin Fold equations and formulas to estimate body density from the measurement which is then used to estimate percent fat. The two equations that withstood most tests with minimum prediction error (3.6% to 3.8%) are mentioned here.

Body Density for Male

Equations include girth measurement:

1.0990750 – 0.0008209 (X2) + 0.0000026 (X2)2 – 0.0002017 (X3) – 0.005675 (X4) + 0.018586 (X5). Where X2 = sum of the chest, abdomen and thigh skin folds in mm, X3 = age in years, X4 = waist circumference in cm, and X5 = forearm circumference in cm.

3-Site Skin Fold Equation

Body Density = 1.10938 – (0.0008267 x sum of chest, abdomen and thigh skin folds in mm) + (0.0000016 x square of the sum of chest, abdomen and thigh) – (0.0002574 x age).

7-Site Skin Fold Equation

Body Density = 1.112 – (0.00043499 x sum of skin folds) + (0.00000055 x square of the sum of skin fold sites) – (0.00028826 x age), where the skin fold sites (measured in mm) are: Chest, Axilla, Tricep, Sub-scapular, Abdominal, Suprailiac and Thigh.

Body Density For Females

Equation that includes girth measurements

Body Density = 1. 1470292 – 0.0009376 (X3) + 0.0000030 (X3)2 – 0.0001156 (X4) – 0.0005839 (X5), Where: X3 = sum of triceps, thigh and Suprailiac skin folds, in mm, X4 = age in years and X5 = gluteal circumference in cm.

3-Site Skin Fold Equation

Body Density = 1.0994921 – (0.0009929 x sum of triceps, thigh and Suprailiac skin folds) + (0.0000023 x square of the sum of triceps, thigh and Suprailiac skin folds)

7-Site Skin Fold Equation

Body Density = 1.097 – (0.00046971 x sum of skin folds) + (0.00000056 x square of the sum of skin fold sites) – (0.00012828 x age), where the skin fold sites (measured in mm) are: Chest, Axilla, Tricep, Sub scapular, Abdominal, Suprailiac and Thigh.

Once the body fat is determined we have to apply SIRI equation. SIRI equation is based on two premises. Our body is made up with two essential components: fat free mass (bone, water, lean tissue etc) and fat mass. The ideal density of these two components should be (a) fat-free mass = 1.10 grams per cc and (b) fat mass = 0.9 grams per cc.

Once we have decided the body density with the help of above equations, BF% or Body Fat % can be determined by the following SIRI equation.

Body Fat % = (495 / Body Density) – 450.

The table below shows the ideal body fat percentage recommended by the American Council on Exercise:

Category

Men

Women

Essential Fat

2% to 4%

10% to 12%

Athletes

6% to 13%

14% to 20%

Fitness

14% to 17%

21% to 24%

Acceptable

18% to 25%

25% to 31%

Obese

26% or more

32% or more