One of the things about dieting is that you end up having to weigh and / or measure yourself quite a lot. My relationship with scales is almost as complicated as my relationship with food, and the tired old bathroom scales we had at the start of the year had a number of flaws.
- My eyesight isn’t really good enough to read them accurately
- The reported weight varies a lot – you can weigh yourself four times in quick succession and get answers that differ by up to 3lb, so the weekly weight check becomes more of an average estimation
- We suspected (based on intermittent use of other machines) that the scales were weighing light
So I purchased a new shiny set of digital scales from Argos. These have a readout which doesn’t vary even if you do step on and off the scales 10 times, and which is legible from a distance of 5 foot 2 (the approximate distance between my eyes and my feet).
There is always going to be some fluctuation however – weight does change daily, based upon a bunch of factors which will be obvious to anyone who’s ever had to try and lose weight. So in order to calibrate the scales with respect to eachother, I used them both for an extended period (11 days). The graph below shows this measurement fluctuation over time, by plotting change in weight across both machines. The faint line is a moving average over a 3-day window.
The delta between the two measurements had a mean of -7.022lb, which shows that the old machine was indeed weighing light. Whoops.
The new scales also measure fat%, bone%, and water% presumably using some kind of conductance (they have metal plates for your feet and instructions not to use if you have a pacemaker). The fat% and water% measurements vary quite a lot, and don’t seem to have a trend yet, but I will monitor them over longer time periods and update accordingly. Bone% didn’t change at all during the 11 days of recording everything, so I guess that’s reliable.
 For the progress graphs on this blog, a 7lb increase will be applied retrospectively to old-scale measurements from earlier in the year.