Wonky scale readings... NOT a FitBit scale.

[Kameleahn]

So, silly me - I went out and bought a different (read: cheaper) scale for measuring weight, body fat, hydration, muscle mass, etc.  And I'm getting some seriously bizarro readings on it.  I'm female, 41, 5'9", 142 lbs, fairly sedentary, except that I walk everywhere.  My scale says that my body fat ratio is 20%, and that my bone mass is 4.2?  Seriously, there is NO way that my body fat ratio is that low - I know 'skinny fat' when I see it, mostly because I've been looking at it in the mirror most of my adult life (something I'm trying to work on now).  But the bone mass measurement just totally freaked me out - that's the healthy bone mass for someone way shorter and WAY lighter than me.  I take calcium and magnesium, and as a super-klutz, I know from experience that I don't break easily.  So should I just assume that this scale is a POS?  For what it's worth, it measures my muscle mass at about 35% and my hydration at about 55%, which seems high - is it mistaking fat for water/muscle?  Thoughts?

[Ukase]

Most body composition scales -- well, all of them really - are about as accurate as me looking at you and guessing your weight, height and I.Q.

The scale can display your weight with some accuracy, but the rest of the values are dependant upon your hydration level.

For example, I have a Taylor "biggest loser" scale. I step on it, I weigh 218 pounds with a body fat% of 32. (69.76 lbs)

I grab 3 large textbooks (over 20 pounds) and balance them on my head. All of a sudden, I weigh 243 with a body fat % of 39%. (94.77 lbs)

Somehow, my body fat measurement grew because of added weight.

I put the books down.

I drink a bottle of water. (16 ounces)

Now, I weigh 219, but my initial body fat% drops to 29%. (63.51 lbs)

So....I drink water, and all of a sudden, I'm not as fat as I was.

I take a caliper test, and my body fat is only 17.8%.

I would return the scale. Use the Fitbit weight log page, and enter your measurements. When water weight is trying to trick you into thinking you're wasting your time, seeing that your waist went down 5 inches since Christmas is a good motivator. Take a selfie, and write the date on the back. Then, take another in a month or two. Compare them. Forget the scale. How do you feel? It's about being fit, not being slimmer.