The Hacker's Diet - January 2008

4 more pounds lost in January. I didn't really plan it that way -- again, like in December, I would have been happy with 3 but I'll take it! I was afraid that the Las Vegas trip in the middle of the month would mess things up but I didn't eat much while I was there so it was a wash I guess.

Since the start of the diet I've lost 18 pounds and I have 12 to go. So I'm 60% of the way there. My BMI dropped into the 27's about a week ago. None of my pants fit properly but I'm still going to wait until I lose those last 12 lbs before I buy more pants.

In January I worked out 18 of the 31 days, averaging only 263 calories per workout. I think this is a good happy medium where I don't get too worn out by exercising on an empty stomach.

Now here's something tangible.

I've been attempting to record calories eaten per day. I have two full months of data to work with. Check this out (all units are calories)

Avg. consumed per day: 1741
Avg. loss per day: 412
Avg. workout per day: 136

From these numbers I can compute how many calories I burn on average each day WITHOUT working out. That is, if I do not work on a given day this is how many calories I would burn just sitting around:

1741 + (412 - 136) = 2017. Let's just call it 2000 calories a day. That's my allowance.

Lost in January: 4 lbs
Total Loss since starting Diet: 18 lbs

Halfway There

This week I made it half-way to my goal of 30 lbs down -- my trend line passed 175 sometime on Tuesday night. 15 pounds lost, 15 pounds to go.

Let's review some stats.

• 15 lbs lost in 16 weeks
• Starting BMI: 30.41 (technically "obese")
• Current BMI: 28.30
• Calories Lost (3500 x 15) = 52,500. That's a lot of calories!

Say hello to my new best friends.

• 100-Calorie Yogurt (the Thick and Creamy is the BEST).
• Lean Cuisine. 300 Calories for lunch.
• A 100-Calorie Dorito pack for an afternoon snack.
• Lots and Lots of Decaf Coffee.

The above regime allows me to get home in the evening after having consumed only 500 calories, which is especially great if I start off the day burning 200-300 calories at the gym. Not a bad trick.

At the rate I'm going I should reach my goal of 30 lbs lost in another 16 weeks -- sometime around my birthday in April. That will be a nice present. Maybe I'll buy myself a thong.

The Hacker's Diet - December

Its a good thing I had low expectations of December. I was convinced that I could not keep up a pound a week diet with all the parties and celebrations and days inside. I told myself I would be happy if I could lose three pounds in December and you know what? I just made it, just barely.


This is a weight trend/time graph from the day I started the Hacker's Diet until yesterday (the end of the year). Look at the last two weeks of December! It was actually going backwards there for a while -- the peak of that little bump is Christmas Day itself. It was a total binge-fest. Almost uninterrupted feasting all day.

But I was successful in my expectations: the month started at 179.1 and ended at 176.1, exactly three pounds. Take THAT Santa.

I have a similar goal for January -- 3 to 4 more lbs. These lowered expectations are because of a four day trip to Las Vegas where I do not intend to be counting calories. :)

Lost in December: 3 lbs


Total Loss since starting Diet: 14 lbs

NYT Article - Overestimating your Calorie Counts

A New York Times article from earlier this month laughs about how people often wildly overestimate the number of calories they think they are burning when they workout.

The entire article is worth reading but here are some interesting bullet points:

• Holding onto the handle bar while doing cardio reduces your burn rate by 50% for some machines. I know that's certainly true when using a treadmill on a steep setting -- by holding on to the handle bar or grips you can make your body perpendicular to the tread, effectively making the surface flat again. D'oh!
  
• Machines drift in speed and grade. This is certainly true in my experience -- after becoming familiar with a set of elliptical trainers for example you may start subconsciously (or consciously!) choosing the one that seems "easier" than the others. I'm as guilty as the next person of this.
• Subtract the calories you would have burned sitting on your ass. For example, suppose I walk on a treadmill for 30 minutes and the counter says I burned, oh, 200 calories. Well if I'd been sitting around watching TV for 30 minutes I would have burned 40 calories. So how many more calories can I eat today? 160. Three Oreos, not four. As the Hacker's Diet says, it's better to just not eat them the in first place rather than try to burn them off!

If you are following the Hacker's Diet religiously and you are measuring every calorie that you are putting in your system, then you know exactly how many calories you are burning. Therefore you can tell how accurate your machines are because you can measure them against your spreadsheet.

But if you're like me and you have somewhat of a life, you have to estimate many of your restaurant meals and various "Goodies" that you might be treating yourself to and you can't really be sure how accurate your count is.

So I try to underestimate my calorie counts and mentally compare them to "was that workout really as hard as walking for one hour, which would have burned 300 calories?"

You know what's sad? I'm eating Doritos while I write this. But its a 100 calorie bag -- the little chips are like the size of a nickel. Not bad.

The Hacker's Diet - Forecasting

At the beginning of the Hacker's Diet, I started a tab in my excel spreadsheet called "Forecast". I plotted a line that assumed the loss of a single pound each week. At the time it seemed like kind of a crazy, optimistic idea that one might undertake with only blind optimism as one's guide.

And initially, the Forecast chart didn't seem to give me much, but it gave me something to look at while the hunger gnawed at my gut.

However, now that about 10 weeks have passed the graph looks like of cool. Check it out.


The blue line is the one-pound-a-week forecast line. Obviously its going to be a straight line, right?

The green line is the actual weight on the scale every Monday for the last 10 weeks. Taking a one-week measure kind of has the same effect of a moving average.

The orange line (in the middle) is the Hacker's Diet Trend Line (see my previous blog entry). I shouldn't be, but I'm surprised at how straight the trend line is.

So this graph allows us to compare two different types of moving averages -- the exponentially-weighted smoothing average with a period of 20 (orange) versus the crude green sampling every 7 days. The green line is more accurate but the orange line provides us with a better way to forecast. The green line appears to lead the orange line by about 10 days (or 1.5 lbs or so). Very interesting. Even better, the green line leads the blue "forecast" line by 2.5 lbs, which means I'm ahead of schedule.

We're going to Las Vegas again next month (don't try to break into my place, there will be someone there), and according to the forecast, I'll be 19 lbs lighter than when I started my diet. How cool is that? Then I might look better than this picture from earlier this year.

Yeah that's me the fatty on the left

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 Hacker's Diet - November

I was on a ROLL during November. I was militant about the diet and I joined a new gym, this one much closer with all new equipment. I worked out 2 out of 3 days for a total of 21 days and 8,500 calories burned. Remember, a pound of fat is 3500 calories.

The weight just fell off during November. I remember waking up in the morning after having worked out the day before and skipping dinner and being beyond hunger; I should have been hungry but wasn't. At one point I felt like I had extra skin on my stomach -- maybe it was loose from losing weight so fast.
Each morning I would plug the latest weight number into my spreadsheet and watch it drag the trendline down a little bit and it would give me such satisfaction!

Who knew that seeing your weight go down by .2 lbs could be so thrilling?

I began to experience a feeling of victory-in-progress, of invincibility even. I know that sounds silly but it was working so well. Even the day after thanksgiving I woke up and weighed myself and STILL the trendline went down.

Needless to say, I am quite proud of November. I consider it no small feat to generate a deficit of almost 50% of the calories you need every single day for a month.

Lost in November: 6lbs

Total Loss Since Starting Diet: 10.7lbs