T Nation

Bad bf readings?

What is all this about the Tanita scales measuring higher bodyfat than you actually have? Mine says I’m 157 lbs, 11%BF, but I obviously can’t tell if this is correct by looking at myself . How should I interpret this? I always weigh in on it at the end of the day after I take a piss(to get out any excess h2o). Anybody know how to interpret these things?

I recall my concern with comparing 'low electro current type (there is term for it)testing to that of calipers. I had an low current test done by a guy I usually see, and then had a caliper test (6 point test) from a trained coach (done a few thousand tests) and had another test done on a low-end tanita unit by a ‘nutritionist’ for overweight people. The comparisons between the first test were pretty close to the pinch test (.25 to .5 of a %) though the third test on a Tanita varied considerably due to the ‘general’ athlete or couch potato settings. My finding is that top end low current BF testers are pretty accurate for BF readings, more so than the ‘home test’ test units. I assume that the higher-end units contain more complex calculations, which at the end of the day, is all BF readings are, a bunch of factors calculated to approximate a variable. I’ve been advised that factors such as taking a test lying down to avoid unnecessary resistance to the current, consuming allot of water & avoiding exercise & caffeine 24hrs prior to testing can make a large difference in readings - my thoughts only.

I carry a lot more fat than you, but here is my current experience. My Tanita scale shows me at 35% pure lard. My training partner has a Masters in Exercise Phys. and measures me with calipers at 14.5%. (Most all of my fat is midsection, under my abs) I measured last month in a mobile hydrostatic tank and it was 24.5%, which is accurate. Now I use the Tanita just for tracking trends, not for an accurate number. If I was anywhere near 11%, I would probably throw the thing away and just be happy.

I’ve noticed the exact opposite results. My Tanita scale always measures me LOW. With calipers I measure at 8% (that was pre Mag-10 and eating like crazy, probably a bit higher now). The Tanita says I’m 5.5%. I thought it may be the result of a low carb diet, but I’ve been carbing like crazy the past two weeks, and Tanita only went up to 6.5%. Measurements are always taken at the same time of day (first thing in the morning, empty stomach, after relieving any excess ‘water’). Measurements later in the day vary slightly, but not much.

I can gain over 2% bf in an hour on my Tanita, depending on what I drink and eat. And mine also reads about 10% higher than calipers. On low carb diets, even when I get leaner and hold my weight, it reads a higher %. Carb ups is just the opposite. My point? Take the lowest number you get and tell everyone that’s what you are…

I like that idea. I am now officially 10%bf. Hey, where are my abs?