I don’t normally agree with Matthew Yglesias, but his experience with weight loss seems to parallel my own:
The biggest gym-related thing I’ve done to lose weight is that I did some sessions with a personal trainer who warned me up front that you can’t really lose weight in the gym—you need to eat less food.
As one who has worked hard to stay in shape, exercising regularly, I have not (until recently) watched what I ate. Then, when I realized that was putting on weight, despite regular exercise, I needed to act.
So, I started keeping track of what I ate, cut out certain things and found that jeans that once fit snugly quickly became more comfortable. And people started taking notice.
Now, perhaps, I might not have needed to cut my calorie intake as much as I did, given how much I’ve been sitting at my desk blogging and working on my dissertation. Yglesias points out that:
It is worth pointing out, though, that for all the apparent gluttony of the contemporary American lifestyle, Americans actually don’t consume a particularly large number of calories in historical terms. Estimates I’ve seen of medieval calorie consumption often go up to 4,000 a day or more. But it’s not that medieval peasants were fat, or that they were really rigorous about doing 40 minutes on the elliptical machine every day. . . .
The bulk of human history was spent with our bodies operating at a generally higher metabolic level than happens nowadays.