Can anyone explain the mystery of the missing 12lb?

[simmi]

According to my quality Beurer scale on 27th Aug my weight was 227lb and my bmi was 30%
so in other words I was carrying 68.1lb of fat.

3 months later my weight was 196lb and my bmi was 25% so was carrying 49lb of fat.

If the scales are right then I have lost 31lb but only 19lb of fat.

How about the other 12lb I have lost? I have been working out 6 times a week so find it hard to believe I have lost muscle mass.

 

[T.M.H.N.E.T]

According to my quality Beurer scale on 27th Aug my weight was 227lb and my bmi was 30%
so in other words I was carrying 68.1lb of fat.

3 months later my weight was 196lb and my bmi was 25% so was carrying 49lb of fat.

If the scales are right then I have lost 31lb but only 19lb of fat.

I've never heard of a scale that can accurately distinguish what the weight is on it. A normal bathroom scaleset would have told you that you were 227lbs in total,like BMI equivalents they cannot accurately gauge what portion of weight standing on them is, fat,muscle,bone or your lunch. Hugely hugely misguided metric for weightloss.

How about the other 12lb I have lost? I have been working out 6 times a week so find it hard to believe I have lost muscle mass.

That assumes that BMI scales are accurate (which they can not be)

In reality weightloss is a product of your diet which you haven't posted. But you could well be losing muscle,in reality a fair portion of it will be as simple as water. There isn't enough information to go on.

But if you want a truly accurate number, go see someone competent in bodyfat caliper usage

 

[poynedexter]

my guy in the gym uses some electronic device that passes a current from toe to finger. then out pops a % based on the different resistance between fat/muscle/water. you have to lie on the floor for some reason.

 

[CopperCyclist]

Your problem is in assuming that the BMI is anywhere near a competent technique for measuring body fat - it isn't.

 

[vickster]

BMI is just a calculation of ration of height vs weight (it's not a percentage per se afaik) -

Not knowing how tall you are means it isn;t possible to calculate, but I am surprised losing 31lbs (a little over 2 stone) took you from 30 (obese) to 25 (normal)

http://www.nhs.uk/Tools/Pages/Healthyweightcalculator.aspx

As above, need calipers to calculate fat %

Well done on the weight loss

 

[tadpole]

According to my quality Beurer scale on 27th Aug my weight was 227lb and my bmi was 30%
so in other words I was carrying 68.1lb of fat.

3 months later my weight was 196lb and my bmi was 25% so was carrying 49lb of fat.

If the scales are right then I have lost 31lb but only 19lb of fat.

How about the other 12lb I have lost? I have been working out 6 times a week so find it hard to believe I have lost muscle mass.

if you've really only lost 19lb of fat, then the rest of the loss will be lean body mass,(LMB) or in simple terms Muscle.

 

[Sittingduck]

Presumably you have been in quite big calorie deficit, for the last 3 months? I think you are going to have lost some lean mass, along with fat - working out, or not. No workout (assuming weight training here) would doubtless have seen you lose a higher proportion of lean mass, so I think it's a case of retaining as much as possible, during weight loss.

 

[Rob3rt]

my guy in the gym uses some electronic device that passes a current from toe to finger. then out pops a % based on the different resistance between fat/muscle/water. you have to lie on the floor for some reason.

These are not accurate and the number's can vary wildly on a number of factors, for example, how well hydrated you are.

 

[400bhp]

water

 

[VamP]

These are not accurate and the number's can vary wildly on a number of factors, for example, how well hydrated you are.

They are actually reasonably consistent in their inaccuracy, so for individual progress purposes they're fine.

 

[srw]

1. The original numbers might be BMI or body fat percentage. They're different measures and without knowing how tall the OP is it's impossible to tell which.

2. Body fat percentage measurements (even using callipers) are never accurate to more than 2 or 3 percentage points. Over time they're a decent indication and can give a rough target weight.

3. BMI is OK as a crude indication of a decent weight - unless you're muscle-bound or an international athlete.

4. The amount of muscle mass won't vary by more than a few pounds at most. If you've been working out 6 times a week you won't have lost muscle mass.

5. Actual weight and measured fat percentage will vary because of hydration levels. Hydration levels are always changing, especially if you're a woman.

6. Well done. You've lost a decent amount of weight and kept up a punishing exercise schedule. Keep it up.

 

[T.M.H.N.E.T]

1. The original numbers might be BMI or body fat percentage. They're different measures and without knowing how tall the OP is it's impossible to tell which.

The OP was standing on BMI calculating scales

2. Body fat percentage measurements (even using callipers) are never accurate to more than 2 or 3 percentage points. Over time they're a decent indication and can give a rough target weight.

2-3% is much better measure than a scale which is essentially a pressure pad measuring force applied to it,and some mathematics to show some figures on an LCD. BF calipers are based on skin folds,there is margin for error if the measurements are taken wrongly/in the wrong places - BMI scales are based on absolutely NOTHING but a guess.

3. BMI is OK as a crude indication of a decent weight - unless you're muscle-bound or an international athlete.

It is crude but simply not ok.

4. The amount of muscle mass won't vary by more than a few pounds at most. If you've been working out 6 times a week you won't have lost muscle mass.

You will if your diet is insufficient.

5. Actual weight and measured fat percentage will vary because of hydration levels. Hydration levels are always changing, especially if you're a woman.

Indeed

6. Well done. You've lost a decent amount of weight and kept up a punishing exercise schedule. Keep it up.

Also indeed

 

[Drago]

Only a sedentary person should be using the BMI system, as all the people measured to create the datum were sedentary. Plus the initial work on developing the system took place when food rationing was still in force, so even by the standards of sedentary folk the subjects are unrepresentative. The BMI can often be as much as 13 or 14% out for a big muscly sort.

Must accurate results are achieved by a combination of calipers, skin resistance resting, and the water displacement method. Alas, I own neither calipers, a skin tester or a suitably large tank so I use the US military method, which was at least designed for active people.

 

[amaferanga]

if you've really only lost 19lb of fat, then the rest of the loss will be lean body mass,(LMB) or in simple terms Muscle.

He hasn't lost 12 lbs of muscle.

 

[srw]

Only a sedentary person should be using the BMI system, as all the people measured to create the datum were sedentary.

For the typical value of "not sedentary", weight doesn't vary all that much from the typical value of "sedentary". It's only Muscle Marys and international athletes who really need to worry that BMI is a terrible guide. For most of us it's OK.