Just to show how deceptive the scales can be, I have a client that weighed approx 116kg when he first started with me. Similar situation to many others- depression, sleep apnea, knee injury, etc.
Anyway, due to the knee injury (and his dislike of boxing) we pretty much had to concentrate on weight training circuits (the only other equipment he had available). Over time his fitness improved but the scales never moved. This same guy now weighs 106kg, but his body shape is anything but overweight. He has a chest, solid arms, the lot. He actually asked me if we could tone it down a bit because he was finding it hard to fit into his suits. The chest back and arms were getting too tight!
Not too many 48y.o's would complain about that, eh!
I have pretty sophisticated testing machines and I also use other methods to back my tests up (My clients get a 15 page report after each fitness assessment). If this guy was just using the scales he would have thought that he'd just lost a few kg in fat, but in reality he'd lost loads more, and added loads of muscle as well.
Yes, go the measurements!
Just in case you haven't seen it, check out this article: Home Fitness Assessment
Ray
My new book:
Winners Do What Losers Don't