Originally Posted by tmil206
Thank you so much for the info and the link. It seems like to me that when you lose weight the scale automatically drops body fat %. However, if for instance you stayed the same weight but lost fat and gained the same amount of muscle I'm not sure if it could REALLY tell.
I just got a Tanita BC533 Innerscan scale, and love it... so here is my take on the mind behind the machine
When you lose weight, the scale does not drop your body fat % automatically. It is possible to look "thin" but really have a unhealthy body fat level, and for that matter, a person can look big and have a lot of muscle.
The thing with the BIA scales that use the electric current is that they are very affected by your hydration level. If you are dehydrated, then the scale "reads" you as having less muscle/more fat. So, say you wake up in the morning, go to the bathroom and run to your scale to see how you are doing... after a long night of rest (and no water), you will be dehydrated. For me, a long-time morning weigher, this is a new realization. Of course, I used to like the fact that I weighed the least in the morning BECAUSE I was dehydrated
The best time to weigh in/get scanned is 3 hours after any of these:
- Waking up
- A hard workout
- Drinking alcohol
You should also make sure you are getting in at least 6 cups of water a day, for health reasons and to make the fat readout closer to reality
Even with these caveats, the BIA scales can be off +/- 5%. It's not a perfect science but it's a great motivator and it DOES give you a close number.
Another blurb for women: because of our monthly cycles, our bodies are all over the place for water content weekly, so it is suggested that for the 1st month you have such a scale, to scan daily to get a "baseline" average that takes into account PMS bloating and loss... then with that in hand, to scan body fat levels only 2x/month because muscle/fat changes are a sloooow process
and scanning more than that is not going to give you any real valid numbers.