Sunday, August 3, 2008

21,700 calories

Cascade peak.

Yesterday I went hiking with Brady, my brother-in-law. We started at 4:30 AM and got done around 3 PM. We hiked up Cascade, a mountain who's elevation is 10,908 feet. Provo's elevation is 4,551 feet.

It's basically a mile straight up.

This post isn't about the hike. That'll be another post.

This post is about the my bathroom scale and how it responded to this hike.

I woke up at 3:56 in the morning to get ready for the hike. I brushed my teeth, showered, drank some water for th
e trip, and decided to weigh myself just to see how I was doing.

A few months back when I had moved to Utah I purchased one of those fancy glass bathroom scales that measures body fat, H2O, and bone percentages. It seemed like a good thing to pick up since I was going to the gym and trying to get back in shape; this would give me a good way to set goals for fitness.

My mother had received one over Christmas, only her's was a nicer model. Her's measured muscle mass on top of the other things I listed.
I figured that muscle mass would be nice to know but wasn't worth the extra $20.

When I measured myself on my mother's scale over Christmas, it said I weighed 162 lbs and 6% body fat. I didn't expect those same numbers 3 months later because I hadn't gone to the gym for about 6 weeks due to moving and working on a film set at the time, but I was still hopeful. On the scale I purchased, it said I weighed 158 lbs and 20.8% body fat.

According to this scale, in about 2 months I more than tripled my body fat percentage and lost 4 lbs. I assumed the weight discrepancy was lost muscle mass and the added body fat was because I had eaten pizza for dinner for about a week while moving and hadn't gone to the gym.

Yesterday I noticed something odd. When I weighed myself in the morning it said 153.4 lbs and 18.1% body fat. After the hike, it said 150.2 lbs and 17% body fat. After eating a bowl of spaghetti and taking a 20 minute nap, it said 153.2 lbs and 18.2% body fat. After going to a symphony and eating a very tasty buffalo burger at a restaurant, it said 154.3 lbs and 19.1% body fat. This morning, 156.4 and 19.8% body fat.

For those not familiar with human physicality and nutrition, one pound of weight equates to roughly 3,500 calories. If my bathroom scale is accurate, it means that yesterday I burned 12,100 calories hiking (I ate about 1,600 calories in trail mix and snacks during the hike), the proceeded to eat

21,700 calories? I doubt it.

21,700 calories over the course of the next 7 hours. That equates to eating 31 Big Macs from McDonald's.

Looking at what I ate yesterday and estimating on the high end of calorie intake, I'm certain I didn't eat more than 4,500. By "estimating on the high end" I mean that my beloved Men's Health recently reported that diners often underestimate the calories in their food by as much as 50%; so I'm taking the estimate I originally came up with and adding 50% to it, even though I highly doubt the burger I ate contained 2,100 calories. I have no idea how many calories I burned yesterday in total, but according to a calorie calculator I burned 4,506 calories just during the hike yesterday. My body should burn about 2,400 calories in a standard day, so taking half of that (from 3 PM to midnight) and adding that to the 4,506 I figure I probably burned around 5,706 calories.

Let's do the math together: calories eaten (4,500) - calories burned during hike (4,506) - calories burned during normal daily activities (1,200) = net caloric difference (-1,206)
≠ calories the scale said I must have eaten (21,700).

A net caloric difference of -1,206 does not equate to gaining 3 lbs (presuming the original reading of 153.4 was correct). Granted some of the weight could be water, but that doesn't explain the body fat % increase.

This can only mean that my bathroom scale is inaccurate.

Being the scientist that I am, I decided to test this further.

I noticed that the body fat % on the scale fluctuated directly with my body weight. While normally this makes sense, if I've been going to the gym, going running, and eating healthy, while my body fat % should decrease it would not be uncommon for my body weight to increase. This has never occurred according to this scale.

I grabbed a toolkit from our closet; I assumed it weighed about 10-15 lbs. This would be perfect to test the scale. While holding the toolkit I stood on the scale again: 171 lbs. Body fat %? 23.1.

Yep; holding a 15 lbs toolkit raised my body fat by 4 percent.

This scale claims it sends a current through your feet and measures the resistance to gauge body fat percentages (fat has a different resistance than muscle). Yet somehow holding a toolkit manages to increase my body fat even though the resistance in my body didn't change at all; no change in resistance should mean that the body has the same composition of fat and muscle and as such should give the same body fat percentage.

What this means is that all this $60 scale does is take your inputted height, measures your weight when you stand on it, and using those two variables performs a fixed calculation to determine what your body fat percentage must be.


It's completely bogus.

If you're looking to get a scale to measure body fat, go with one of the high end ones that measures muscle mass as well. This one just measures weight and estimates your body fat. It's quite worthless for fitness purposes.

My father taught me when I was young that you get what you pay for. He was right; I should have spent the extra $20.


Becky said...

1) Your margins are a little off and some of your text is missing off the edge--you probably noticed that already
2) Keep in mind that your body weight can fluctuate by drinking water, going to the bathroom, etc, so it does not mean that your body processed thousands of calories to gain or lose weight suddenly. The body fat thing, though, yeah, that's a little hokey; it certainly doesn't change that fast, or with a toolkit at your side.

Becky said...

okay, maybe it was just my computer--the margins look fine now.