Lost 58 pounds and only 9% body fat?

BIW2012

When I started losing weight I had my body fat percentage measured. I'm perplexed by the numbers - lost 58 pounds and apparently only 9% body fat?

Stats were

Weight: 236 pounds
BF: 48%

Just this week, I was measured by my personal trainer. My new stats are:

Weight: 178 pounds
BF: 39%

= loss of 58 lbs and 9% body fat.

Something doesn't add up for me: If I'm aiming for a healthy body fat % of around 25%, going by the numbers above, I'll need to lose around another 87 pounds or so!

Does anyone out there know more about BF % than me?

Note: The before and after measurements were taken on two different scales. One with a nutritionist and one with a personal trainer. Both professionals have good equipment and charge $70-$95 per hour. Looks like one of the scales might be out, but it seems like it would have to me way out!

runfreddyrun

were you measured by calipers? unless you had your body fat measured in a bod pod, hydrostatic (water) tank or by a dexa scan, it likely has a large margin of error.

also, when you lose weight, you typically lose fat and muscle - just how much depends on many factors like how much you're eating, how much protein and whether you're also doing strength training.

my advice? get your body fat checked at a body pod or dexa scan, then you'll know what you're really working with. i think bod pod is the cheapest of the three with almost as low margin of error. universities usually have them.

btw - you didn't exactly lose 9% body fat, even if both measurements were accurate.

weight: 236
bf%: 48
fat lbs: 113.3
lean muscle lbs: 122.7

weight: 178
bf%: 39
fat lbs: 69.4
lean muscle lbs: 108.6

so for your 58 lbs lost, 43.9 of those were fat and 14.1 were muscle. that's actually not that bad. that's about a 3/1 ratio of fat to muscle lost, which i understand is quite decent.

are you doing strength training? if not, you might want to start. it will help you hold on to even more muscle.

BIW2012

Wow thanks guys - you went to so much trouble to do all those calculations. I really appreciate your time!

Sounds like it's not quite as simple as I thought. I would have lost a bit of muscle last year as I was way under-eating and only doing cardio.

I'm doing some strength now - 30DS. Not hard core lifting but I have definitely build more muscle.

I'd love to do one of those more accurate measurements as I'd like to focus on a body fat % goal rather than a weight goal.