<p>The digital scales today are cheap and accurate. They use four load sensor/strain guages at the feet. I have found my Tanita to be accurate and highly repeatable.</p>
<p>Like anything else, these appear to be manufactured in the same two or three factories and sold under various brands. Taylor and “Biggest Loser” and others at the low end. Tanita and Omron at the high end. When I was shopping, the Tanita models were heavier, more robust, and seems to use much larger, more substantial load sensors.</p>
<p>If I were buying one today, I would go for something very simple. Just stand on it and read the weight, ideally with large lighted numerals so I could read it in a dark bathroom, first thing in the morning, without my glasses! Something like this in black glass:</p>
<p>[Amazon.com:</a> Tanita HD-366: Health & Personal Care](<a href=“http://www.amazon.com/Tanita-Digital-Weight-Scale-HD-366/dp/B002N6FR0M/ref=sr_1_11?s=hpc&ie=UTF8&qid=1305729284&sr=1-11]Amazon.com:”>http://www.amazon.com/Tanita-Digital-Weight-Scale-HD-366/dp/B002N6FR0M/ref=sr_1_11?s=hpc&ie=UTF8&qid=1305729284&sr=1-11)</p>
<p>You can get a similar scale from Taylor for as little as $25.</p>
<p>As you go up in price, you get the scales that attempt to measure body fat. </p>
<p>[Amazon.com:</a> Tanita BC534 Glass InnerScan Body Composition Monitor: Health & Personal Care](<a href=“http://www.amazon.com/Tanita-BC534-InnerScan-Composition-Monitor/dp/B0007Y6BRK/ref=sr_1_10?s=hpc&ie=UTF8&qid=1305732033&sr=1-10]Amazon.com:”>http://www.amazon.com/Tanita-BC534-InnerScan-Composition-Monitor/dp/B0007Y6BRK/ref=sr_1_10?s=hpc&ie=UTF8&qid=1305732033&sr=1-10)</p>
<p>This is largely a waste of money. It is neither accurate nor repeatable and is only mildly entertaining. The Tanita approach is to use on-board look-up tables based on the gender, age, height, activity level you program in your “button” along with the measured weight and some factor applied to the impedance of a tiny electrical current passed thru your body (essentially measuring water). This means that each member of the family has to have their own programmed button, which of course they will never understand or use. This adds needless complexity because you have to press a button before you stand on the scale (although there is a simple “weight” button). About all I can say for it is that the Tanita algorithm does result in body fat numbers generally trending down as you lose fat, but with significant day to day fluctuation.</p>
<p>The other “step-up” feature is memory – storing anywhere from the last one to a hundred measurements. Mine has a recall feature for the last measured weigth for each of the four people (buttons). It’s a little handy if you forget before you write it in your log, but otherwise not a very important feature.</p>