One thing I haven't talked about is that I'm on a diet for the first time in my life. I've never terribly much needed one (well, not for more than a month or two, anyway); my weight used to fluctuate between 172 (most of the year) to 168 (ultimate frisbee off-season. Late November through mid-March, roughly). The only time it's gotten significantly higher was shortly after I met my wife; I gained close to twenty pounds back then.
I lost most of that right after we returned from visiting her parents in Hong Kong. I got miserably sick for a week or so after (might have been SARS, although I was never diagnosed. The timing and symptoms were right, at least). Regardless of what it was, I lost ten or so pounds while recovering. Then, I got back to my normal weight a couple months later, once frisbee season started again.
So, I've never really needed to lose weight. The one time I really tried was... six or eight years ago, when I just decided to try exercising a bit harder than normal. I got down to about 163 doing that; I was exercising very hard, but only every couple of days (at least, I think that's why I didn't lose more).
I still didn't turn to diet, and I have no regrets about that.
When I started biking heavily, maybe six months ago, I wasn't really trying to lose weight, per se, although part of the reason that I started biking in the mornings was hearing that exercising in a fasted state was much better for fat burning. And I think my experience bears that out. I ended up losing about twenty pounds, getting down to 155#, which, partway through, I'd kind of set as my target, as that was my weight when I graduated from high school (and was doing a lot of sports, as well as some running and significant weight lifting). It was also convenient because biking looks at power as W/kg, and that's almost exactly 70kg.
Through all that, my diet was a bit of a mess. I did ok on keeping fat intake low, but my carb intake was ridiculously high. Also, when I realized I needed to cut back a bit on the biking intensity, I gained back a few of those pounds (3-5 of them).
After hearing quite a bit about the benefits of ketosis, I was thinking about a ketogenic diet, although I didn't really know what that entailed. When I found out the Atkins diet is ketogenic, and reading quite a bit about the benefits (blood chemistry and such), I decided to give it a try. I eased into it (partially to get food out of the house, partially because I'm not real strict on counting carbs) while I read the latest version of the book on it.
Since I was already basically at my target weight, I decided to skip the first two phases of the diet, and go straight to Pre-Maintenance. The good part about that is that it's much easier; the bad part is that I didn't have to get real strict about counting (I also eat out enough that it's difficult to do).
But what I've found is that I have lost some weight. I'm currently down to about 152. Logically, this seemed likely, but given the extreme disregard I've given to calories, it still feels a little weird. I haven't told my wife about it either, as she's currently dieting to lose weight (just through calorie deprivation, which she's successfully used before. After each kid, basically); I suspect it might make her upset.
The hard part, for me, is just making sure that I get enough foundation vegetables each day. Also, I've had some trouble with wanting to eat more; I suspect that's because I don't eat enough fat (it certainly isn't due to not eating enough, overall). And I've occasionally had cravings (yesterday, I had the worst hankering for some orange juice, which was part of my normal breakfast before I started the diet).
Overall, I'm not sure what to make of the results. Biking hasn't suffered at all, so far as I can tell; my peak power numbers for February (I started roughly two weeks ago) are a significant improvement on January, whose numbers were only a hair better than December. There are some other factors that might be of significance there (in particular, going to a polarized training model from the old "no pain, no gain" model), but it certainly hasn't hurt.
I do need to talk to my doctor, to see about doing bloodwork (and I wish I'd done that before starting, just to have a baseline) as part of my (overdue, most likely) annual check-up. I don't expect anything to come out of that, but I'm curious.
The one thing I wonder about is whether my body is in ketosis. I found a simple blood test to tell, and it isn't terribly expensive, but the strips to repeat the tests are ridiculously expensive (almost five dollars per test last I checked). Maybe I'll break down and start paying that, but I'm reluctant.
Anyway, nothing further to talk about, but it's interesting to me. I'm very curious to see where my weight stabilizes.