Thursday 11 January 2007

Pic of the day: "This fried fish really is larger than a sardine!" This girl from the anime Magikano is not used to eating as much as she wants. I am, but on the other hand I don't want as much as I can eat.

More weight, less eating

My weight gain seems to have stagnated, still below my former normal level. Actually my current normal level would probably be higher, since the balance point tends to slide gently upward with age until our 60es sometime, varying by genetic background. Perhaps I will never again reach that, since I can eat so little fat. A year ago, I compensated by eating furiously the things I could eat: Carbohydrates, and lots of them. But as I have regained weight slowly over this past year, my wolf- like appetite gradually faded. I am probably eating a bit more than I did two years ago (before the purgatory weeks) but less of it is fat.

As I have hammered into my regular readers for so long, fat is not just twice as calorie-dense as carbs or protein. It has two other dramatic differences relating to weight gain. One, it can be stored in the body with only minor modifications, and very little loss of energy. Carbohydrates can only be stored temporarily and in limited quantity, otherwise they have to be converted to fat. This conversion is ridiculously inefficient in humans, so that much of the energy is being lost as heat. Protein, as we know, can only be stored in the body by building muscular tissue; otherwise it too will be burned (and create extra work for the kidneys in the process). Okay, all this was part of point one. Point two is that the feedback loop for fat is slow: Your total fat storage determines your appetite in the long run, while sugar causes your body's flame to flare up in the short run, causing you to radiate more heat than you otherwise would. (If your fat deposits are low, this counteracts the "flare-up" part, as your metabolism is put in miser mode. But this requires you to have approximately 12-15% less fat than your natural "set point". I tried this last year, as you may remember. The theory certainly seems correct to me.)

I am not sure how much of my reduced appetite comes from the hormonal pathways in the brain, in response to the increased leptin content in the blood. (Leptin is the signal molecule leaked into the blood by dedicated fat deposits, so-called adipose tissue. It acts as a hormone of sorts, though the effect on the appetite seems to be indirect through a chemical pathway in the brain. But let this not become a gray entry here.) In my case, part of the feedback may be more immediate: The fat has once again – more than ever, I'd say – gathered around my intestines, kidneys and thereabouts. It pressures directly on my intestines and indirectly on my stomach, so I probably feel "full" earlier than I otherwise would, in a purely mechanical way as well.

I wonder if I would have eaten more if my fat had settled more evenly all over my body, and on my hips and thighs, like it does in children and women respectively. Oh, and breasts are mostly fat too. Young men should take this to heart. Anyway! Without the direct feeling of fat around my digestive tract, would I have felt more inclined to eat? I guess there is no way I'll find out now. Somehow the ways to find out are not very appealing. (Castration would do that, or eating moderate amounts of female hormones. I don't really think I'll do that for science. Though the hormones would be kind of cool, then I could see how they affected my mind too. Hmm. Perhaps I'd catch up on my journal then ... by far most prolific diary writers have female sex hormones in the bloodstream. Though they have come to them naturally. Due to a lamentable lack of photos, I cannot ascertain their fat deposits, while you have probably have had more than enough of mine for years.)