The Hacker's Diet -- Examining the Trend line

To me, the most fascinating aspect of the Hacker's Diet is the Trend Line. The trend line is a simply a moving average, or more precisely, an exponentially-weighted smoothing average of the previous weights. The formula for its calculation is simple enough.

Let t be the trend and let t-zero be yesterday's trend.

The trend adjusts itself by taking one tenth of the difference between today's measurement and the existing trend. So if you are 2 lbs lighter on the scale then trend, the trend will adjust downward by 0.2lbs.Why divide by 10? Taking a tenth of the difference as your true signal provides a nice, smoothing effect. Let's take a look at how the smoothing effect works. Here's a contrived example: You weigh 177 at the start of the month and immediately lose two pounds so that your true weight is 175. Of course you vary a little from day to day (let's say alternating between 174 and 176). Here's what the trend line looks like:

The red line is the trend line. It appears to take the entire month to finally match your true weight of 175! Is this a good thing or a bad thing?

Its bad in the sense that for three weeks or more you are operating under the assumption that you are losing weight when you are not. But its good in the sense that you are carrying forward your credit so you can coast for a while and still appear to lose weight!

Using a larger multiplier, like say 0.3 (dividing by 3.33) gives a little bit of smoothing, but not much. As a result it becomes much more "accurate" in that it achieves you true weight in only 10 days or so. Here's what that looks like:


In the end, I must say it probably comes down to some level of personal preference. I find the 0.1 multiplier to be not just smoothing, but soothing.

The Culprit

For the last four years I had gained about a pound every month, leading to 40+ lbs over 4 years. This even though I was somewhat active; going to the gym, spending all day fly-fishing, etc. After reading The Hacker's Diet, I did some math and determined that I was consuming about 150 calories too much per day.

Well I know exactly where this surplus came from.

For years I have started each and every day with an evil concoction whose gluttony-enducing seduction is matched only by its massive amount of calories. The dreaded White Chocolate Mocha!

Yes, I have had one of those liquid bon-bons every day for the last four years. According to the Starbuck's nutritional site, a 12 ounce white chocolate mocha is 300+ calories. If I had instead been drinking just coffee and cream this whole time I would have lost 10 pounds a year instead of gaining 10 pounds a year.

I immediately gave up the white evil and as a result, if I don't do anything else, I'm going to lose all that weight -- it just might take four years. And you know what? That would be okay with me.