Ask an expert

12 Dec 2002

Body Fat - fluctuations
Hi FitnessDoc,
I have had my body fat percentage measured a few times since August and I'm amazed at the wild fluctuations! In August, it was part of a full medical and they used the electrodes on various points in my body (which I understand is the most accurate measure). In those days, it was 34%, and my weight was 72kg's (I am 1.69m). At the time, I had an undiagnosed under-active thyroid (in fact, this was picked up at the same medical), and had gained 12kg's as a result. In Nov, after starting medication, following a diet, embarking on an exercise program etc, I had it done again by a dietician, who had an electronic scale which apparently sent minute impulses through the soles of the feet and gave a reading. It measured 35% (!!!), although my weight was down to 65kg. The dietician explained that this reading was often inflated by about 5% (I think it was more to calm me down than anything else...). In late Nov, I went to a BodyIQ biokenticist, and she measured with calipers, and gave me reading of between 25 and 27%. Finally, this morning, I went to a BodyIQ Health Zone and was measured again and this time, it came out at 12.6%!!!!!
Now, I am apple shaped and carry all my weight around my middle. I admit that my arms and legs are very lean and possibly out of proportion for the rest of my body, but I am sure that I am not so round that simply including my abdomial measurements could make such a dramatic difference! My waist measurement is 78cm and my hips 97cm. What's the deal? Is it possible to get an accurate reading on this, and if so, what would you recommend.
Much appreciated and apologies for the lengthy essay!
Answer 413 views

01 Jan 0001

Hi ajay

Unfortunately, any measure of body fat is subject to some degree of error, and you are right, depending on your fat distribution, methods will vary according to where fat is measured. The last reading sounds partiularly low and far off fomr the previous readings. Your best bet is to go with one technique and stick with that eg. electrodes or callipers, then you will be comparing apples to apples - however, even from one day to the next, repeatability erroes can occur. For this reason, I would recommend that you focus more on your waist and hip measurements. From a health perspective, your waist should be less than 80cm.

Exercise regularly (4 to 5 times a week) and eat a low fat healthy diet and you should lose excess fat. Perhaps use a similar programe to the one you were originally on and keep track of your measurments throughout.

Good luck!
The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical examination, diagnosis and formal advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.