glow notes

Friday, April 15, 2005

Complexity theory

My husband has a population biology degree. This morning he explained to me how ecosystems have multiple points of equilibrium. For example, a pond with X number of fish will tend toward X number of fish even if something upsets the equilibrium, but that number may change. That sounded more confusing that I meant it to. OK: a pond hosts 1500 fish. A predator eats 200. The pond will bounce back to 1500. Or, there is a good season for fly larva and the population bounces up to 2000 - it will bounce back down to 1500 over a time. BUT, if the predator eats 300, the new equilibrium might be 1000. OR, if there is a really good season, the new equilibrium may go up to 2200. That's because it's a complex system.

So, that got us talking about our body/mind/spirits as a complex system. In terms of weight (one metric, arguably not the most important one, but easy to measure). I have a set point at 165. When I went up to 172, it was relatively easy to get back down to 165, but getting below it was rough. My next set point is about 148. Again, once I got below 165, getting to 148 was relatively easy. My next set point is 135 . . . Etc. Now that I'm below 130, I suspect my next set point will be around 125, at which point I'll have to push a little harder to get to my goal weight of 120.

The converse is that if I creep back up a pound or two, my body will reach for the higher set point. I've seen this more than once with weight re-gain. I stabilize at, say, 138, relax for awhile, and WHOMP, I'm suddenly 148 again.

It's like a hilly running course - the downhills are easy, but the up hill sections are tough. The places in between are set points, or equilibrium points.

Why is this? Well, we're theorizing it's because we're complex systems. A lot goes into weight loss and fitness, some of it psychological, some of it hormonal, some of it physical. Food tastes change. Muscle mass changes, and thus basal metabolic rate changes. Who you spend time with changes. Your level of activity changes.

Wow! What this means, if true, is that, when weight loss is hard, you can a) understand that if you're doing the right things to meet your goals, you may just be at one of those set points and you'll see change soon and b) if you change some variables, you will likely get through the hilly sections faster. Variables to change can be all sorts of things, from getting a massage to eating more for a day (then getting right back on target), to switching up your macronutrient profile (e.g. more protein, more carbs). It's a matter of experimentation.

More thinking on this will surely be posted soon.

I'd love to hear what you have to say. Do you see this in your body?


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