brianogilvie 

+1. As John Walker observes in The Hacker's Diet, one common response to the emotional toll of daily fluctuations is to weigh yourself only once a week. But how depressing is it when the weekly weigh-in is higher than the previous week?

By weighing yourself every day at the same time, and plotting the exponentially weighted average, you can get a much better idea of where your weight is trending. If your daily weigh-in is usually under the curve, then you're almost certainly losing weight. If it's usually over the curve, you're almost certainly gaining weight. If it fluctuates back and forth, you're stable.

Another tool for doing this kind of tracking is Beeminder, which uses negative reinforcement: you can use it free when you start, but if you fall off the wagon, you need to commit some money to continue to use it. Each time you fall off, the amount of money you commit to restart is greater. I just discovered it, so if you want to see how it works in practice, you can visit my weight loss graph. I started on Jan. 9. I've had a few days when my weight has gone up, including today - 1.6 lbs. higher than yesterday. But it's still below the exponentially weighted average (or "skinny purple line"), so I'm fairly confident that it's fluctuation caused by water retention or eating a lot of roughage in my dinner yesterday, which happened to be vegan.

I find that the emotional toll of seeing a higher number is much less when I can visualize it against a falling average. The exponentially weighted provides an objective counter to the subjective sense that the bigger number means that I've gained weight. It also lets you put those big losses into perspective: you know that the 4.5 lbs. that you lost in a week were not all fat; the average shows you how much of that loss is (likely to be) really lost fat, and how much of it is differences in water, fiber, etc. from day to day.