This makes perfect sense. Thank you!We have a biometric impedance scale - stand on it and it reports your fat%, lean body mass, bone mass, etc. HOWEVER - since going low carb it is not reliable. Here's why:
Uusing impedance is based on the different degree of electrical conductivity of different tissues (specifically body fat vs all other tissues, based on the better conductivity of water and the amount of bound water in the tissues). The studies were all done on a typical diet, which contains a large amount of carbohydrate, leading to a significant amount of water in the non-fat tissues, especially the muscle tissues. One of the benefits of low carb, of course, is the shedding of all that excess bound water ... which means the electrical conductivity of the muscle mass is now reduced and so its mass will be reported to be less. The impedance (reverse of conductivity) scale then subtracts muscle mass, adjusts the implied bone mass to support that muscle mass, probably doesn't change the factor for internal organs (based on height) - and so tells you less muscle, less bone and therefore more fat.
Total mass (weight) - organ mass (essentially fixed) - muscle mass (now under-reported) - bone mass (ditto) = fat mass (over-reported)
So don't worry about it. Remember the scale is a lousy proxy for body composition, which is a fair proxy for health. Which of these is really important to you? For me it's the last one; the strength that comes along with better body composition is good, too - but actually a part of long-term health for me.