Body Fat scales**personal trainers & fitness nuts

I want to see what others say...

I have my activity level set to sedenitary as I work at a desk for 8 hours a night.

From what I've read, the scales can't accurately calculate body fat percentage. I use calculators on websites where you input your measurements to get an estimate, but even those aren't very accurate.

Personally, I'm somewhere between unemployed and work from home (I'm an artist and web publisher who is looking, but not finding, a "real" job), and I say I'm lightly active. I'm mildly hyper and fidgety, so I don't sit for long. I'm always playing with the dog, up and down steps, cleaning this or that. I don't include the amount I exercise in my activity level, though, since I add those calories back into what I eat and don't want to double dip.

I do get a bit of a chuckle out of their description of lightly active as a nurse or salesperson. Sales can be anything from someone carrying a Kirby Vacuum door to door, to someone who sits at a desk and makes calls. Nurses... good ones, at least, are CRAZY active. I've never been a people-nurse, but as a vet tech, I busted my *kitten*, and the only time I got to sit and rest was when I went to the bathroom! :laugh:

I'm a certified trainer and personally, I think most of the devices that you can use to measure body fat percentage and all of that are extremely inaccurate. The most accurate types are typically expensive and require a full body scan (like a DEXA machine) to give a better indication. The most popular device I've seen people use to measure their body fat is the bioelectrical impedence. This one is extremely portable, but also has a pretty high margin of error. For example, if you are not perfectly hydrated when you use this device, your measurements will be way off. Also, if you hold it too close to your body, your measurements will be off. Personally, I feel that these types of devices can be used as guidelines, but I wouldn't rely on the readout 100%. Since we tend to be creatures of habit, they'll give you a decent indication of where you're at and if you're improving, but that's about it.

That's just one example of one device. But most of the home-use devices are similar to that as far as error goes. The Biggest Loser scale you're talking about would also be inaccurate if it doesn't take into account lifestyle, gender, age, and height. It would give you an indication of where you should be at, but again, it's not a good idea to rely 100% on the information.

As for your lifestyle setting on MFP, I think what you said is just fine. If you're sticking to your plan and seeing results, that's the most important thing. If you're finding that you're not losing anything and you've increased your frequency, intensity or time for your workouts, then you might see what it's like for you to change your lifestyle to sedentary since that'll decrease your calorie intake.

Hope that's helpful!

I am not an expert, but here is my experience--
I use a Tanita scale that measures body fat, water, muscle mass, etc. through bioelectrical impedance analysis. I did lots of reading and research and went into it knowing that it would not be exactly accurate. But for me, it has been incredibly helpful, as others have said, as a relative measure of progress and how I am doing from one week to the next. So I don't take it as gospel that THIS is my body fat percentage exactly, but rather, how is it relative to last week's measure? But the most important comparison for me is in terms of muscle mass. It helps me tremendously in not going through the agonizing that many of us do about "is this weight gain from my workouts--adding muscle--or fat??" For example--three weeks ago I was down about a pound in body weight. Happy, right? Not so much, as it said that relative to the week before I had actually lost that in lean muscle mass and had actually gained a slight amount in fat percentage. That made sense to me in terms of what was going on in my life that week--I was away on vacation, and hadn't worked out much and had overeaten a bit, so the loss of muscle and gain of fat made sense. Fast forward to this past week--when I weighed in I was up almost a pound!! But I wasn't too unhappy because, relative to previous measurements, I was up in muscle mass and had lost in fat percentage--yay!! And this made sense in terms of my life experiences, because I had spent the past two weeks really increasing the intensity of my workouts, adding more weight lifting, and really watching my food intake. Don't know how scientific or exact this all is, but it works for me!!