Now, this is “only” 3.6 pounds a week, but that’s still a 12,600 kcal/week deficit. And here the interesting thing: I go back to LoseIt!, and I find that I’ve been running something more like a 4200 kcal/week deficit. In other words, I seem to be losing weight at something like 3 times the rate that would be predicted by simply looking at the calorie deficit. Oh, and that calorie deficit from LoseIt! accounts for calories expended in exercise — the working out has been included.

In other words, the “calories are calories” model doesn’t seem to account for the real results. The usual explanation for that is “oh, that’s just water weight.” But over the month and a bit in which I lost 23 pounds, if I was averaging that 4200 kcal/week deficit — or 600 kcal/day — for all 32 days, that would predict a loss of about 5.5 pounds. So, we need to account for 23-5.5=17.5 lbs of water. A gallon of water weighs 8.35 lbs, so that is 2.1 gallons of water. For the water explanation to hold, I would need to have lost, and sustained the loss of, over two gallons of water.

That’s a lot. (And I can tell you, I’m exhibiting no clinical signs of dehydration.)

Now, another possible objection is that I must have not been keeping the food diary accurately; all I can say is I’ve been religious about it. But consider, I’ve been eating less than 2500 kcal/day. For it to be the food intake, we have to account for another 2500 kcal/day. I’m a big boy, but I promise you I hadn’t been eating 5000+ kcal a day before I started this; it seems very unlikely that I could have been much under 2500 kcal and still feel like I’ve been eating plenty, as I do. Hell, my big splurge day, 3 November, just before I started the experiment, including 2 Double Whoppers with Cheese and a large fries, as well as a big sweet tea. Even on that I only managed to eat a little under 3200 kcal. And I was uncomfortably stuffed for much of the afternoon.

It really looks like this “calories are calories” model isn’t fitting my experimental results.