Since I boasted on my blog that I was aiming to get down to 82 kilos for the Marathon, my weight has stagnated somewhat around the 85-86 kilo mark. I tried knocking off an extra 100 calories a day but eventually I gave up counting calories altogether. I think that it was probably a more useful exercise when I was having to cope with the kind of training volume I was undertaking for the Ironman because, more often than not, it was a question of making sure I was eating enough, often enough. Coupled with the fact that the latest firmware update on the Garmin 310XT now awards me around about 25% more calories per run, I decided instead to go by gut feeling (sorry). On the days when I have no training I have to consciously hold back and the rest of the time I eat according to hunger. Simple. People have been doing it for millions of years before the iPhone was invented.
(By the way, I was surprised that the other runners on my training camp in Morocco were so careful about what they eat that they made me feel like a glutton. I'd assumed that they weighed around 60 kilos because of their frame, their metabolism and the amount of training they did.)
But, being an obsessive sort of person, I need to have feedback to know that I am going in the right direction as well as to encourage me. The problem with weighing myself is that, although bathroom scales are now very accurate, my weight fluctuates tremendously during the day and during the week due to how hydrated I am at any particular moment. The said bathroom scales can also measure body fat by impedance: by shooting a mild current through your feet it can make a guess at your body composition based on how much resistance you offer. This seems to be even more sensitive to how hydrated you are. The results are so random that it is almost impossible to see a trend. Short of having my body fat measured professionally in a "bod pod" or by submerging me in a bath of water, the next best thing is to use a pair of calipers. I picked up some from Amazon for about 10 euros. They measure body fat in the most crude and obvious way, by measuring the width of your skin folds.
There are several formulas to estimate your body fat, all based on taking skin fold measurements from several key points around the body. A commonly used one is the Jackson Pollock formula. More information and a calculator are available on this website.