Calories in, calories out

I’ve been reading a few too many fat acceptance blogs over the past several days, and I keep seeing one claim repeated over and over: dieting doesn’t work, “calories in, calories out” is flawed. The party line among these people seems to be that their metabolism has simply — and irreversibly — crashed from years and years of yo-yo dieting and it is simply impossible for them to reduce their calorie intake to a weight-loss producing level without starving themselves. And starving, of course, is bad for you.

Now, I’ve been actively trying to lose weight for the better part of the last year, and up until a couple of weeks ago, I was convinced that something was seriously wrong with me because I could not lose any weight. If you had asked me, I might have come up with the same rationale: my metabolism must be shot, I just can’t eat few enough calories.

During a short-lived moment of increased morale a while ago, I postulated that I just gain muscle easily, and I was replacing any fat I lost with muscle, and that’s why I wasn’t losing any weight. I resolved that THE SCALE IS EVIL AND IT LIES and to ignore it and concentrate on other things, like measurements. Tape measures don’t lie. But in the absence of any hard data to back up this theory, I felt like I was just making excuses for myself and I soon gave up again.

Some time ago I read the Hacker’s Diet, which espouses the “scale is evil and it lies” theory, and compensates for this with an Excel macro you can use to calculate a moving average of your daily weight readings and extract some truth from what the scale is telling you. But I don’t have Excel. So I just filed it under “that’s interesting” and moved on.

But then a few weeks ago I discovered PhysicsDiet, a website-based version of the same tools that the Hacker’s Diet uses. I signed up right away, bought a digital body fat monitoring scale, and almost immediately found out something very interesting. Based on the changes in my body fat percentage along with my weight, I’ve been gaining about a third of a pound of lean mass (likely muscle, right?) every week. I’m not sure at this point whether that is unusual for people in general or for women in general, but I have a sneaking suspicion that it isn’t unusual for people with my kind of build.

This is my weight loss graph for the last couple of weeks.

I am weighing in consistently below the trend line, so I’m losing weight, but look at that trend line. It started off strong but got a bit shallower last week and today it actually leveled off. I hope this is temporary, because it’s not very encouraging.

My body fat percentage graph tells a different story, however:

Look at how nice and straight that trend line is! Look how it’s been steadily going down this whole time! That’s what I like to see. This is the whole point of what I’m doing, and what I should be focusing on.

I’m rapidly realizing that the number on the scale is really irrelevant. My body fat percentage is what I should be basing any goals on.

You may have heard people saying that the BMI (body mass index) is inaccurate. BMI is just the ratio of your weight in kilograms to your height in meters squared. That’s all it takes into account — your height and your weight. Anyone who tries to tell you that BMI is an accurate measure of body fat is full of shit.

The popular example is a fat guy and a body builder who are the same weight and height — and therefore have the same BMI — except that, obviously, the body builder’s weight is mostly muscle while the fat guy’s is mostly fat. BMI would call them both obese, but clearly only one of them is.

Well, that’s an extreme case, you say. Surely for a “normal” person, BMI is an appropriate method of measuring fatness, right? Take my case. I don’t consider myself especially athletic or muscle-bound. The “healthy” range for BMI is 19-25. For my height (5′0″), that’s a range from 97 to about 127 pounds. According to my body fat percentage, I have 95 pounds of lean mass. At 97 pounds, I would have only two pounds of fat on my entire body! I would have 2% body fat. Essential fat for women is 12-15%. (American Council on Exercise guidelines, via Wikipedia)

Acceptable body fat percentage for non-athletic women is 20-31%. For me, at my current amount of lean mass, that covers a weight range from 118 to 137 pounds. Think about that the next time you’re tempted to call a woman “fat” just from knowing her height and weight. Remember, I don’t consider myself a terribly unusual case.

This has gotten a bit too long, so: Next time on “CG blogs about weight issues”, what does “size acceptance” mean, and what’s up with “fat Monica”?

Tags: Health