This design review looks at body fat scale for home use and recommends the best scale that can meet proposed technical specifications. Body Fat Scales are also known as Body Composition Scales. While the latest modern scale can tell us alot of useful information, this review focuses on the most common concern, which is “fat”.
Types of Body Fats And Uses
The first thing you need to know when using body fat scale is to measure visceral fat.
When we discuss about body fat, the focus is normally at the belly, even though they also tend to gather around buttocks and thighs.
Belly fat consists of the following 2 types in the simplest term:
- Subcutaneous fat is located just under the skin, which your fingers can pinch and pull. This includes those at the buttock and thighs. Subcutaneous fat is useful as cushion, insulation from cold, and reserve source of energy.
- Viscerat fat is wrapped around the belly’s internal organs which you cannot touch or see. Visceral fat could never be zero for a living person, and some visceral fat may help to protect the abdominal organs. However, too much visceral fats is detrimental to health.
Problem With Visceral Fats
Visceral fat is not the same as fatty liver. Visceral fat refers to those adipose (fat) tissues around all the organs, fatty liver refers to fat accumulated in the liver (steatosis) itself, which will subsequently lead to fatty liver disease (Steatohepatitis). Steatohepatitis includes both non-alcoholic (NAFLD) and alcoholic (AFLD) disease, which may cause scarring and even lead to cancer . According to this Hepatology study , it was concluded that visceral fat is associated with fatty liver disease.
In another study, excessive visceral fat could be linked to type 2 diabetes, insulin resistance, hypertension, and cardiovascular disease. So even though our body requires optimal body fat to stay healthy, it is important to keep harmful visceral fats within acceptable range.
How To Measure Visceral Fat At Home?
It is important to note visceral fat is difficult to measure as they are wrapped around our internal organs.
In the hospital, visceral fats can be measured by Ultrasound (US), Computed Tomography(CT scan), and the more accurate Magnetic Resonance Imaging(MRI) and Dual-Energy X-ray Absorptiometry(DEXA or DXA). All of these equipments are expensive and requires special arrangment with the hospital or clinic. They are more accurate than home body fat scales, but they are not meant to be used on a regular basis. For the purpose of self-monitoring on a weekly or daily basis, a good home-based body fat scale would suffice.
At home, visceral fats can be estimated in 3 ways:
- Waist circumference measurement using tape measure. It is a crude method and the stomach must be relaxed when measuring.
- Men: 40in (35.5in for Asian)
- Women: 35in (31.5in for Asian)
- Body Fat Scale using BIA method
- 4 electrodes: Measuring by passing current between left and right feet (4 points).
- 8 electrodes: Measuring by both hands and feet (8 points).
Bioelecrical Impedence Analysis (BIA)
BIA (Bioelectrical Impedence Analysis) is a method for estimating body composition by passing a weak AC electric current through the body to read the impedance (resistance). As water conducts electricity, BIA basically measures the TBW (Total Body Water) including extra-cellular and intra-cellular water. In layman terms, they are the water outside and inside the cells.
However, fat cells has very little water of about 1-7%, while there could be as much as 75-80% intracellular water in lean mass. So by measuring the current and TBW, the BIA can estimate the FFM (Fat Free Mass). Then theoretically, the BFM (Body Fat Mass) is obtained by subtracting:
Total Body Mass – FFM = BFM
Where Total Body Mass is obtained from the scale, and FFM is obtained via BIA from the Gray’s equation. This method is not as accurate as DEXA or MRI, but it is a practical and good way to estimate the body fat status for home and daily use. We do not need to know the exact amount of visceral fat to the last digit, but it is suffice to know that it is within the desired range.
There are alot of studies on BIA to compare with hospital methods, such as this involving 104 participants: where they found subjects with BMI < 25, BIA correlated best with CT measures of visceral fat.
Known Issues With BIA
- The FFM equation does not seem to include estimation for the bone mass. The bone mass has a different water content as fat and muscle. We believe the calculation has an estimation on this, which contributes some error.
- The visceral fat and some of the body composition data is affected by the height and age data. You can try this test:
- Enter the age as 30 years old, and take the measurement.
- Then change the age as 50 years old, and take the measurement again.
For the same “body”, the visceral fat level for the 50 year old will be higher than the 30 years old. The problem with the age-based visceral fat discrepancy is obvious with feet-only BIA measurement that uses empirical formulas involving age, gender, etc.
An example is the full body scale such as the Inbody H2Ob with 8 tactile electrodes for both hands and feet. It uses direct impedance measurement and does will not fluctuate based on the age, gender, but requires the height information.
Note that not all 8-electrode scales are the same as Inbody scales. Tanita’s RD-545 8-electrodes full body scale, uses their own patented formula but include age, gender and height in the estimation. This means that their results may also fluctuate depending on your age.
Body Fat Scale Technical Specifications
The following are the suggested design or technical specifications to review in a Body Fat Scale.
The Body Fat Scales for full body measurement should have at least 8 tactile electrodes, comprising 4 each for hands and feet. The scales with 4 electrodes that only measure from the feet is far from accurate especially for the elderly above 50 years old. As explained above, elderly folks should get more accurate results by using 8 electrode body fat scales. Such scales come with a retractable handle with 4 electrodes, in addition to the 4 on the scale that is stepped on.
Studies have shown that multiple frequency BIA is strongly co-related to the DEXA method. The use of different frequency enables measurement of extracellular and intracellular water, as explained in this article on MF BIA:
|“…a current with a frequency of around 50 kHz can penetrate the cell membrane, and currents with lower frequency bands from 1 kHz to 20 kHz pass through to the extracellular fluid. Moreover, it has been reported that a current with a frequency band from 100 to 200 kHz passes through both the extracellular and intracellular fluid by the loss of the cell membrane…”|
A total of 484 participants in a BIA accuracy study showed that segmental multi-frequency BIA is a valid tool when compared to the highly accurate DEXA.
- Mobile App
The scale must come with smartphone App to keep track of measurement data.
- Support Multiple Users
It must be able to support multiple users.
At least one year of warranty from the date of purchase.
Body Fat Scale Options
Based on the above design specifications and our research, we have selected 2 models from reputable brands for further evaluation.
- This is the only scale that meets all our requirements above.
- It is classified as a class II medical device, and support remote tracking.
- Inbody uses patented direct impedance measurement instead of empirical formula. The results are not affected by age and gender.
- Inbody has just one model for home use and that is enough, since it can meet all the specs.
- Our comments are as follows:
1) It is expensive at $349, which is about 10x the price of the cheapest 4-electrode Body Fat Scale in the market. We do not mind paying for more accurate scale, however, Inbody should provide a high quality protective bag for storage or carrying around.
2) At this price, we expect more items on the report. It only has 7 items, which is lesser than my $20 scale. Fortunately, it has the 7 that I need as well.
- Muscle Mass
- Fat Mass
- Percent Body Fat
- Visceral Fat Level
We are not expecting the same level of comprehensive report such as the one from commercial models below. But the current level of details with only 7 item is quite disappointing. It is like you paid for a Ferrari at full price, but they stick a plug inside the engine to let you drive at only 10% of the full speed.
- RD-545 InnerScan PRO meets all the key requirements as well.
- In addition,
- It has a 2-year warranty
- Full body report has 11 items:
Body Mass Index (BMI)
Body Fat %
Body Water %
Basal Metabolic Rate (BMR)
Visceral Fat Rating
Muscle Quality Score
- Segmental measurement has 3 items, which is good
Body Fat %
Muscle Quality Score
- The drawback is the price that is 28% ($100) more than the Inbody H2Ob.
- Tanita’s BIA include age and gender in their calculation. While the gender and adult height do not change, the age will change with time and so will the results. As Tanita’s BIA is based on 8-electrode, we are uncertain if it is more or less accurate than Inbody’s direct impedance method.
- Tanita RD-545 is worth the price as it can provide more item in its report including segmental measurement data and 2-year warranty.
- Inbody H2Ob has equally good technology but it is not fully utilised to create a more informative report. It also has 1-year less warranty than RD-545.
In conclusion, we will buy the Inbody H2Ob as it meets our key requirement at a lower price by about 28%. Those who can justify and update their needs to spend another $100 can go for Tanita RD-545. If Tanita RD-545 has the same level of report as Inbody’s higher end machinery, then we think its worth the price at $450.
Other 4-Electrode Body Fat Scales
We have tested at least 4 different brands of feet-only, body fat scale with 4-electrodes and find that the results are basically the same. As such, we do not plan to list any models here at this time, as they are relatively cheap and easy to find in local stores. The better quality scales are from Huawei and Omron.
How To Burn Visceral Fat
Everybody has different methods of reducing visceral or body fat. I have achieved mine in two years using a combination of one-hour jogging and proper dieting. The following are some suggestions.
- Exercise for at least 45-60 mins a day. Start at 30mins if its too tough. Alternate between different activities and focus on duration at low-medium intensity.
- Brisk walking
- Eat good breakfast within one hour after waking up, unless you are going for exercise. Lunch is always a good portion of well-balanced diet including carbohydates, protein and fibre.
- Eat a light dinner and avoid all carbohydrates. Salad with lean meat are good choices. For dinner, I have tried:
- Salad with lean meat
- Yoghurt with fruits
- Steamed or soup meat
- Vegetable soup
- Avoid sugary drinks at all times
- Drink more water as it is a natural appetite suppressant.
- Get Enough Sleep
- Quit smoking
- Limit or stop drinking alcohol (Alcohol Fatty Liver Disease)
Check out more suggestions on food to burn visceral fat.