How do the best body fat analyzers work?

fat analizers

The top body fat analyzers, such as this Omron model, use the bioelectrical impedance (BI) method to calculate the user’s specific body fat percentage and body mass. The fat analyzer sends an imperceptible electrical current of 50 kilohertz and 500 microamperes throughout the body to measure the amount of fat tissue. Body fat tissue has little electric conductivity – as opposed to muscle, blood vessels and bone; all fat-free mass whose high content of water easily conducts electricity. The BI method bases its readings on electric resistance plus the distance the electricity traversed. The results are displayed on the unit’s screen in four different ranges; low, normal, high, and very high – according to the body mass index (BMI) value.

Body fat ranges and BMI

 

Age

Low

Normal

High

Very high

BMI*

 

< 18.5

8.5-24.9

25-29.9

> 30

 

Female

20-39

5-20

21-33

34-38

>38

40-59

5-22

23-34

35-40

>40

60-79

5-23

24-36

37-41

>41

 

Male

20-39

5-7

8-20

21-25

>24

40-59

5-10

11-21

22-27

>27

60-79

5-12

13-25

26-30

>30

*(weight (lbs) x703) / height (in) / height (in)

 

BMI (World Health Organization designation)

Less than 18.5

Low

18.5 or more and less than 25

Normal

25 or more and less than 30

High (pre-obese)

30 or more

Very high (obesity)

 

The percentage of body fat is the amount of body fat mass in relation to the total body weight. In other words, body fat mass (lbs) / body weight (lbs) x 100 = body fat percentage (%). Body fat analyzers calculate specific body fat percentage and body mass accurately and as quickly as 7 seconds. However, there are exceptions in which measurement by the device may considerably differ from actual percentage, for instance in these groups of people:

·         Children in a state of growth.

·         Elderly people and post-menopausal women.

·         People with fever.

·         People who have a swelling.

·         People with very low bone density due to osteoporosis.

·         Bodybuilders and professional athletes.

·         Dialysis patients.

Additionally, certain fluctuations may affect a reading, for example 1-2 hours after breakfast, lunch, or dinner; blood circulation changes after a bath or shower, after exercising, in extreme heat or cold, during illness or fatigue; and postural changes such as going from standing upright to lying down. Therefore, measuring of body fat should not take place:

·         Immediately after vigorous physical activity.

·         Immediately after a bath or sauna.

·         After drinking alcohol.

·         In the 1-2 hours after drinking large amounts of water or a meal.

Conversely, the recommended times to measure body fat are as follows:

·         After waking up.

·         2 hours or more after breakfast but before lunch.

·         2 hours or more after lunch and before taking a bath or having dinner.

·         2 or more hours after dinner, before going to bed.

There are several different styles of body fat analyzers. The Omron model used to exemplify this article is vaguely reminiscent of the Knight Rider Gullwing steering wheel. Others are the shape and size of a credit card. And there is also the good old fashioned skin fold caliper, of course.

Related Read:

Reviewing the Omron Fat Loss Monitor