What are the rules of accounting?

In bike racing, the easiest place to lose weight is to get nicer bike parts.  The cheapest is off your body.  A year ago, I decided I should "make race weight" - meaning lose a few pounds. Of course, then Ski Liberty introduced chicken cheese steaks, and a few of those every weekend with large quantities of beer and zero time on the bike and I was quickly back to my usual winter weight - not heavy, by any means, but not as healthy as I could be.

This spring, I focused on eating foods high in protein, keeping snack foods out of the house, and riding at higher intensities.  I'm at a lower 'race weight' now than a year ago.  But here's the thing - I can't tell you how much weight I've lost.  That's because I'm a scientist and can't decide how to measure and report it accurately.  Do I go from heaviest to lightest?  But that doesn't take into account the daily weight fluctuations we all know occur.  So do I guess the heaviest I was in the morning versus the heaviest I am now in the morning?

Wait, I know, I'll give a range with standard deviation - let's say 12 lbs +/- 2. I don't actually have the data to compute standard deviation properly here, but since it's approximately the range for which 95% of the datapoints fall within two standard deviations of the stated mean... uh-oh, that means 12lbs +/- 1.  Final answer.  The quantity of beer in my fridge suggests I won't be able to increase that number much even though it's cross season.

Did I mention I suspect random errors are introduced by my $12 scale?

Of course, I've also recently lightened my bike with some sweet new wheels to go with my $12 scale.  Priorities...