I was a chubby kid, but ever since puberty, I’ve been fortunate that the mix of recreational interests that I’ve had have apparently been enough exercise to keep my weight under control, even for as much as I like to eat (and you can read that “as much…” clause in two different ways, both of which are true). I’ve never engaged in exercise specifically for my health, although I’m certainly glad that there are activities that I enjoy doing (dancing, biking, frisbee…) that count as exercise even if I’m doing them for fun. So, I don’t think about my weight that much. I’m lucky.
Having said all of that, I do realize that not being focused on something is a good recipe for letting it get out of one’s control, and memories of having problems with my weight as a child keep me worried that I could have trouble in the future. Fortunately for me, my own father has a theory about healthy weight-management with which I’ve really jumped on board: “I don’t care how much you weigh, but you should weigh that amount every year.” Suppose you gain two pounds per year. That works out to less than three ounces per month, basically imperceptable. But, if you did that for 25 years, you’d weigh 50 pounds more than you do now. I will not feel at all good about my weight in 25 years if I weight 50 pound more than I do now.
So, the theory says, you’ve got to have a baseline that you keep coming back to. You’ve got to make sure that you don’t fall into this imperceptable creep. Once a year you’ve got to weigh the baseline amount. You pick the date. You pick the weight. But, if you’re not there, do something to get there, every year.
Ok. Now, again, I’m not worried about weighing too much now, so I decided a couple of years ago to set my baseline weight a few pounds more than I weighed at that moment. (Out of respect for the idea that one’s weight is a private matter, I shall not give any absolutely numbers in this public forum. Suffice it to say that the baseline was an amount I’d be perfectly comfortable weighing for the rest of my life). So, I signed up for the plan, and started weight myself more often, which turned out to be about once every three months.
What I found was that my weight varied more than I would have expected it to. The first winter after I started paying attention, I was actually a few pounds over my baseline, which surprised me. I thought “I might actually have to go on a diet”. I decided that I’d set my date for the summer, when it’d be easy to convince myself to increase my exercise level, and lots of fresh vegetables are in season.
What I found, though, was that in the Spring, without even trying, I had dropped back down in weight to a few pounds under my baseline. And, I stayed at about that rate until the next winter, when it went up again.
I don’t know how long this has been going on, but this year I felt motivated to pay some attention to it. Somewhere around the beginning of 2006, I found myself weighing about five pound over my baseline. That caused me some concern. I decided I’d reduce my intake of pop (man, what a fast way to ingest calories pop is!) and have been doing that for months. I don’t know how many, but enough that’d I’d weighed myself a couple of times since then (and I’d say never twice within three weeks), and didn’t notice any real change.
Then suddenly, this past week I weighed myself and I was about three pounds under my baseline. So, something like 6-8 pounds lost, with practically no variation in diet or exercise habits. What gives? And the pattern seems pretty clearly defined: every Winter I put on weight, every Spring it comes back off.
So, I can’t help but ask the question: could there be a seasonal thing going on in humans with their weight?
I did a cursory web search, but this is a hard subject to study on the web. The problem, of course, is that it’s hard to get past the countless self-help weight-loss guides and stuff. Basically, I found a lot of articles about the food served at Xmas parties, but practically nothing about biology.
It’s certainly possible that the holidays have something to do with my weight fluctuation. But, it just doesn’t seem that likely. Yes, my family feasts over the holidays, but that’s only a couple of meals, and I certainly do a fair amount of feasting in my normal existence. Yes, I attend holiday parties, but I attend parties all the time, and there’s always fat-filled finger food and alcohol there, and I don’t feel that I indulge any differently in November and December than I do normally. I could be wrong. Maybe I do and don’t realize it.
But, here’s the opposing case. I’m a relatively good sample set for this experiement. I weigh myself on the same scale, and do my best to keep it well zeroed (it is a pretty crappy scale, so that’s one weakness of my research methods). I eat two meals a day with limited snacking. For lunch, I typically eat at one of the many restaurants near where I work, and this is true throughout the year, and they certainly don’t vary their portion sizes in accord with the season. Dinners are more often than not food that I prepared, and I like eating until I feel a sensation of being “full”. Some things change about the kinds of foods that I eat in the Winter vs. the Spring, but I don’t know how much they’d matter. The most obvious thing is that in the Winter I make more soup, which I don’t consider to be at all bad for me. Throughout the year, but especially when vegetables are good, I make a lot of “stir fries” (interpretting that broadly), and while many people think that vegetable oil is not really bad for you, there’s no question that there’s more fat in my home-fried food than there is in soup, right?
As for activity, well, I haven’t been particularly active recently. As I just wrote in a previous post, I biked more in January and February than I did in March and April. I did some serious binge-dancing at the Pigtown Fling in late March, but come on… And besides, I danced just as hard at Winter Warmup in December, and in general my dance habits haven’t changed much.
So, what I’m suggesting (totally without proof) is that there’s something else going on inside me. I’m not suggesting anything supernatural. But, I think scientists tend to model our bodies as machines more than as animals, and I think this evidences itself in attitudes about nutrition and exercise. I do believe that one will lose weight if one burns more calories than one ingests, but it’s hard to know how many calories one is burning. And, in general, I think many people maintain a stable weight even while ingesting more than they burn. One simple possibility would be that we don’t actually digest all that we ingest. Our GI tract could just let some calories pass through us through its involuntary work. And, if it did that, it doesn’t seem at all unresonable to me that it might vary the amount based on the season. Many if not most living things native to non-equatorial regions have some instinctual sense of the season. Why could this not be true of humans? It doesn’t have to be the GI tract thing, that’s just a random speculation. But, my body does all kinds of things in digesting foods, and I don’t understand them, and there would seem to be countless ways that my cells could do different things with the nutrition I present then that would cause fluctuations in my weight.
I don’t know if this is true or not. Maybe it is, maybe it isn’t. For all I know, it may even be accepted fact among scientists, and I just can’t find their work. I doubt it, though. But, I invite everyone to offer evidence and theory of any kind in support of or opposition to this proto-theory.