Tanita BC-418MA GB 2 Inter-day changes, New Regression Formula for Basal Metabolic Rate BMR

Page 20

GB 2) Inter-day changes

The diagrams below offer examples of actual measurements made of inter-day changes. A study was done to determine the degree of change in the impedance between the feet during dehydration; the first two days represent a normal daily routine, while in the latter two days a state of dehydration was induced using a sauna.

THE APPLICABILITY OF THE OVERSEAS BMR REGRESSION FORMULA AND ITS DIFFERENCES WITH THE OLD FORMULA

The New Regression Formula for Basal Metabolic Rate (BMR)

GB

Intra-day fluctuations (Weight)

61

 

 

 

 

60.5

 

 

 

 

60

 

 

 

 

kg59.5

 

 

 

 

59

 

 

 

 

58.5

 

 

 

 

58

 

 

 

 

1000

1200

1400

1600

1800

 

 

Time

 

 

5/13Monday

◆5/14Tuesday� ▲5/15Wednesday�×5/16Thursday

Intra-day fluctuations (Impedance value)

420

 

 

 

 

410

 

 

 

 

400

 

 

 

 

390

 

 

 

 

Ω 380

 

 

 

 

370

 

 

 

 

360

 

 

 

 

350

 

 

 

 

340

 

 

 

 

1000

1200

1400

1600

1800

 

 

Time

 

 

5/13Monday

◆5/14Tuesday� ▲5/15Wednesday�×5/16Thursday

Intra-day fluctuations (%FAT)

22

 

 

 

 

21

 

 

 

 

20

 

 

 

 

19

 

 

 

 

18

 

 

 

 

17

 

 

 

 

1000

1200

1400

1600

1800

 

 

Time

 

 

5/13Monday

◆5/14Tuesday� ▲5/15Wednesday�×5/16Thursday

No significant inter-day change was measured in body weight, impedance between the feet, or body fat percentage during the normal daily routine. During the dehydrated state, however, a drop in body weight of 1kg was noted, with the impedance between the feet rising approximately 15Ω on the first day of dehydration and 30-35Ω on the second day. As a result, body fat percentage was up by around 1% on the first day of dehydration and by 1.5-2% on the second day.

As mentioned earlier, impedance increases when body weight is reduced (such as by dehydration), and decreases when body weight is increased through excess consumption of food and drink. The inter-day change in impedance is thus inversely proportional to the change in body weight.

These inter-day changes stem from such causes as:

1)Temporary increases in body weight (total body water) through overeating and overdrinking

2)Dehydration due to heavy sweating during vigorous exercise

3)Dehydration due to alcohol consumption or the use of diuretics

4)Dehydration due to heavy sweating during saunas, etc. Accordingly, it is recommended that instructions be provided to the subject to help eliminate these causes when accurate measurements are needed.

It has long been said among medical and nutritional specialists that "The Basal Metabolic Rate (BMR) is more determined by the Fat Free Mass (FFM) than by the body weight" (Persons of a given body weight with a higher FFM will have a higher BMR), and that from the aspect of evaluating the body composition, should be estimated from the FFM. In addition, in cases of simple estimation formulae which can calculate from the height, weight and age, without evaluating the body composition, there was a problem with excessively high evaluations being given to obese persons with large body weight, and conversely excessively small BMR evaluations given to muscular athletes, though these are not as many in number. Currently, the BMR estimation recursion formula developed by Tanita, the manufacturer of body composition analyzers, based on their research, works by multiple regressive analysis using this FFM, and has a higher degree of accuracy in the individual differences in body composition. In order to derive the BMR, resting respiratory metabolism (Resting Energy Expenditure: REE) was measured using a breath gas analysis device, and this estimation recursion formula was created based on this data.

<Figure 1> The Relationship Between Resting Energy Expenditure (REE) According

to Breath Gas Analysis and Weight, FFM

(Presented at Nutrition Week, Held in San Diego in 2002)

 

FFM vs REE

 

Weight vs REE

3000

 

 

 

3000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

breath

2500

 

 

 

Male

 

2500

 

 

 

 

 

 

 

 

 

 

breath

 

 

 

 

Male

 

2000

 

 

 

Female

2000

 

 

 

 

 

from

 

 

 

from

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

kcal/day

1500

 

 

 

 

kcal/day

1500

 

 

 

Female

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

REE(→BMR)

1000

 

 

 

 

REE(→BMR)

1000

 

 

 

 

 

500

 

 

 

 

500

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

 

 

 

 

 

0

 

 

 

 

 

 

10

30

50

70

90

 

30

50

70

90

110

130

 

 

 

FFM kg

 

 

 

 

 

Weght kg

 

 

Inter-day changes in body fat percentage and impedance measured by BIA between the feet during normal daily routine and during dehydration

JP Male JP Female

 

US Male�

US Female

 

JP Male JP Female

 

US Male�

US Female

 

 

 

 

 

 

 

 

 

 

 

 

 

40

41

Image 20
Contents Body Composition Analyzer BC-418MA Safety Notes Power SourceUsage Conditions Storage ConditionsProduct Assembly and Components Digital display Assembly InstructionsMembrane Switch Preparation for Use Loading the Printer Paper RollMode Selection Setting the Original Mode N TStandard Athletic Operating Instructions Body Composition AnalysisSetting of Clothes Weight Explanation of the Print Out Body Fat Ranges for Standard AdultsBased on NIH/WHO BMI Guidelines AgeClearing Paper Jams Components of the Printer Unit Clearing Paper JamsTroubleshooting Problem ListSpecifications Signal lines and connection methods(2).Output data format Transmission data(1).Output data items Switching to Remote Mode Control CommandsError Codes Transmission DataSet gender Set tare weightExample of Use Measurement finished ResettingDuring measurement Voltage Body impedance measurement methodsCurrent Causes of errors in impedance measurements Intra-day fluctuations WeightIntra-day fluctuations cyclic activity within a single day Intra-day fluctuations Impedance valueFFM vs REE Weight vs REE GB 2 Inter-day changesNew Regression Formula for Basal Metabolic Rate BMR Intra-day fluctuations %FATProduct specifications REE→BMR