Friday, March 11, 2011

What We Do and (Usually) Don't Know

In two recent blog posts, Dr. Arya Sharma of the Canadian Obesity Network, uses the same quote from Health Canada:

“Healthy weight is influenced by a number of things, including your lifestyle, environment, metabolism (how quickly you transform food into energy), height, age, and family history/genetics.”

It cannot be said too often: weight loss/maintenance/management is an almost unimaginably complex issue. If you are a regular reader of Dr. Sharma, you'll know that he uses the term "nightmare on ELMM street" to underscore how facile and ultimately unhelpful the notion of "eat less, move more" is.

(Excuse me while I wipe the rotten egg off my face. I know that certain readers are already standing and screaming, red-faced, that "eat less, move more" is indeed the holy grail and if you follow this simple precept to the letter, you will be slim and happy for the rest of your days.)

Well, it just ain't so.

We actually know very little about why people lose or gain weight and the reasons why, all things being equal, Mr. X will maintain while Ms. Y will gain while Ms. A will lose.

People who go on diets know very little about what their bodies are doing. They know their starting weight and can calculate their BMI; and if they count calories, they have a relative idea of how many calories they consume. However, to really understand what is happening in their bodies, they need to know some numbers that are much more difficult to come by.

Do you know your resting basal metabolism (or resting metabolic rate)? In other words, do you know how many calories your body needs to just keep the brain operating and keep you breathing? This rate varies from one person to another...and it accounts for 75% of the calories you burn.

Do you know the percentage of body fat and lean muscle mass you carry? As a woman, you will normally carry considerably more fat than a man. A brief trip around the internet seems to point to an average body fat level of 23-25% for women and somewhere around 17% for men. The body, be it male or female, requires a minimum (essential) level of fat: at least 3-5% for men, 10-12% for women. This is not an "ideal" level, it's a minimum, below which the body will be in serious physiological danger. No, Virginia, anorexia is not good for you.

My scale gives me a body fat percentage in addition to my weight. As far as I'm concerned, the number is not accurate. Personally, I would have more faith in "near infrared interactance" or "dual energy X-ray absorptiometry" though I suspect most people don't have that kind of equipment lying beside their bathroom scale. And yet, knowing your lean muscle mass is such an important piece of knowledge since muscle is more metabolically active than fat. Although muscle may not actually burn a significantly larger number of calories than fat (there seems to be some controversy regarding this issue), it means you're stronger and thus (amongst other things) muscle helps to maintain proper joint function. On a much more superficial level, muscle significantly contributes to shaping and contouring the body.

There is actually one piece of equipment most people do have lying around the house that will give them a much better idea of their muscle development and fat loss: the tape measure. Whenever I hear or read about someone who is lamenting her paltry weight loss, I just want to ask if she's measured herself recently. Losing an inch off the waist is much more significant to one's health status than a several pound weight loss. Alas, many people would rather worship the scale and BMI numbers, neither of which provide them with much valuable information about their fat/muscle ratio.

In a nutshell, without going overboard, it's a good idea to build up more muscle in your body. The whole issue of the number on the scale should go completely out the window. I'll bet you a whole lot of money that those gonzo weight-loss bloggers shouting to the rooftops about how many pounds they've lost in so few weeks are not doing much about building muscle. Are they losing muscle as well as fat (a bad, bad thing to do)? Perhaps. In so doing, is the number on the scale going down faster? Probably. Are they really becoming significantly healthier losing muscle along with some fat (lower number on the scale) rather than re(building) muscle? Questionable. Are they setting themselves up for yo-yoing on the scale? For 95% of them: yes.

Do you know much about how much lean muscle you carry? Have you even thought about it or is the scale your only (and faulty) source of information?

And how much do we know about our metabolism? Again, I suspect not much. Unfortunately, it's the kind of thing a layperson cannot accurately measure. With all the controversy swirling around weight loss and the possibility of a significant drop in metabolism (which makes continuing weight loss much harder and maintenance a nightmare), why do we know so little about such an important factor? Is it because then we would have to question the ELMM mantra? Would the mantra have to change to EL&L&L&MM&M&M to just stop yourself from gaining back those hard lost pounds? Is it because maintenance means literally and figuratively running harder and harder and eating less and less just to stay in the same place?

And while we're on the topic of metabolism, do some people metabolize certain types of food differently from others? For instance, are some of us more sensitive to carbs than others? And if you are sensitive to carbs, what would the Twinkie diet do to you? After all, it worked for Dr. Haub...In my opinion, we need to know a lot more about how different bodies react to different food categories.

But no, like drones we repeat ELMM, ELMM and 95% of us regain the weight...and more.

Simplicity is a wonderful thing. It makes things seem so easy. Unfortunately, the things we don't know and/or the complicating factors we choose to ignore remain lurking in the background, ready to sabotage our seemingly well-laid plans.


  1. Wow ... I'm a regular Dr. Sharma reader and somehow missed the "Nightmare on ELMM St" term ... I love it!!

    I have two concepts I like to use to explain the complexity of obesity. One is the story of the blind men and the elephant, the other is the idea of "wicked problems." (

  2. Hi Beth,

    I have used the "blind men and the elephant story" in previous posts myself. It's very apt.

    Thank you so much for the link to "wicked problems". It's brilliant and certainly worthy of post in itself as it pertains to weight management!!

  3. Tried to leave a comment and it went to limbo. Was just sayin' that yup, I know my resting metabolic rate -- at least from 2008. Need to retest. I've got a fancy schmacy scale that, like you, I don't trust with the details. I simply obsess over the big red number on the plain white scale. It's not sane, but I'm law abiding. Sigh.

  4. Yep, it doesn't make a lick o'sense...
    (the best part of coming back from vacation - catching up on my blog reading!)
    But I indulged myself shamelessly, yet only gained 0.6 lbs?!? I'm supposed to be a smart person, yet I have not the slightest clue in how to explain it (took a week off from the gym too)... Maybe it was all that healthy DRIVING ;-)