It may not be scientific, but it’s what I’m seeing here.

As regular blog readers know, last summer I went on a diet and lost 45 pounds. That translated into four pants sizes (14 down to 6) and more than 20 inches (total) off my bust, waist, and hips.

I did all this in about four months — I started on June 15 and was pretty much off the diet food by October 15.

45 pounds was about 23% of my body weight. A friend, on seeing me in January for the first time in more than two years, said I was 2/3 the person I was. Not exactly accurate; I was closer to 3/4 the person I was.

My point: I lost a ton of weight in a very short time.

The Real Benefit

The benefit — other than looking great — was feeling great. I had (and still have) a ton of energy. I can walk faster, hike longer, and even climb hills without getting winded. And I have a theory about that.

When I was fat — there, I said it! — I was carrying around a lot of extra weight. My body had to adapt to carry that weight — it had to get stronger just to lift that extra weight off the ground and walk with it. When the extra weight disappeared, I still had the strength to carry it, but had nothing to carry.

Imagine being forced, every day of your life, to walk around with a backpack that gets heavier over time. After nine years, it’s 45 pounds. Because the weight was added slowly over time, your body has become accustomed to it and, although it’s not easy to carry, you can carry it because you’re used to carrying it.

Now imagine someone taking weight out of that backpack at the rate of 10+ pounds a month for four months. Your body still has the strength it needs to carry all that extra weight, but now it’s gone! How do you think you’re body’s going to react? It’s going to have all kinds of extra energy that it doesn’t need.

I’ve been putting that energy to good use since this summer by going on long hikes, getting out and about with friends, maintaining an aggressive travel schedule, and keeping active around the house, packing and moving my belongings into storage.

How Metabolism Fits In

Here’s where my theory gets a bit sketchy — mostly because I have no scientific evidence to back it up.

As we age, our metabolism slows down. I think that’s pretty much accepted as fact. Because most of us don’t reduce the amount of food we eat or eat smarter or better as we age, we gain weight. I’m pretty sure that — and normal female hormonal changes — are what caused me to pork up over the years.

After losing all that weight, I worried a lot about gaining it all back when I got off the diet — which required me to eat special food. But I certainly didn’t want to stay on the diet forever. So I weaned myself off the food and tried to eat sensibly.

Then the holidays came and I ate whatever I wanted to. And then I did some more traveling and I ate out a lot. And I spent a lot of time with friends, eating and drinking and having a grand old time.

At this point, I eat almost exactly as I did before I went on the diet. I should be gaining weight, right?

But I’m not. The weight is keeping off me.

And that’s where I think the metabolism is coming into play. I suspect that my weight loss and increased activity levels — because I now have more energy to keep active — has raised my metabolism. My body needs those calories and it burns them off.

What do you think? Does this make sense to anyone who knows about this kind of stuff?