The Speculist

Three more pounds lost at this morning's weigh-in. I'm down a total of 24 pounds so far this year. Woo-hoo!

On the subject of counting calories and monitoring the burning off thereof, reader Ivan Kirgin writes

It is pretty hard to gauge how many calories you burn from activity. You could trust tables like this:

http://www.nutristrategy.com/activitylist4.htm

But who knows how much they apply to a given person.

There are companies like BodyMedia which make medical devices that strap on your arm and glean everything they can. It’s a big sensors and machine learning problem. Apparently they can get a live estimate of the rate at which you’re burning calories, along with dozens of other numbers.

Unfortunately, like any smart company, they are targeting high-end patients like those with insurance and heart problems.

For those of us who’d like to know exactly how many calories we burned in a day, but don’t want to spend thousands of dollars, there seems to be no gadgets available…

WAIT … as I was writing this comment, I found this:

http://www.bodymedia.com/products/bodybugg.jsp

$499 for the “BodyBugg” by BodyMedia. Horrible name, but apparently it’ll track your calorie burning rate & has web tools to upload that info plus food consumption and all.

Phil, you should totally see if your insurance would cover it. I’d certainly like to see someone’s recommendation before I buy something like this. Excellent gadget though.

This sounds like a very neat gadget, and if anyone is using anything like it, I would like to hear from them.

Personally, I'm not so much interested in the burn rate of a particular activity as I am my daily burn rate. That I can calculate to a sufficient level of accuracy using Microsoft Excel and the doctor's scale. I'm using Excel to keep track of every single thing I eat, with an estimated calorie count for each entry. These entries I sum into daily, weekly, and monthly totals. I'm also tracking my weight loss for each of those periods. So the math looks something like this:

Total Calories Per Month / Days in Month = Average Daily Calories Consumed

Average Daily Excess Calories + Average Daily Calories Consumed = Average Daily Calorie Burn Rate

This might make more sense if I plug in some real numbers.

For the month of January, I consumed a grand total of 48379 calories. Divide that by the number of days in the month (I started my program on the second of the month, so I'm only counting 30 days in January), and I get an average calorie consumption rate of around 1613 calories per day.

48379 / 30 = 1613

Over that same period, I lost 19 pounds. There are approximately 3500 calories in a pound of fat, so that means I burned 66500 extra calories.

19 * 3500 = 66500

So my excess calories burned per day were 2217:

6650 / 30 = 2217

And my total calories burned per day were 3829:

1613 + 2217 = 3829

Wow, burning calories at that rate, it's amazing that I was ever fat to begin with! But the truth is, even though as a big guy I do have a pretty high burn rate, the rate shown is almost certainly skewed high. Probably ridiculously so. That's because the bulk of the weight loss in the first month probably wasn't entirely fat -- a lot of it was retained water. However, by scrupulously employing this method for a period of months, I will get an increasingly accurate picture of my burn rate, which (unfortunately) is likely to go down the smaller I get. But by adjusting the rate of calories down, as needed, to compensate for the difference, I will eventually have a very clear picture of what it takes to keep me at a healthy weight.