Uh, oh...

I know I've said similar things here before, but now it's in a Time article. So, you know, it must be true.

It is actually fairly detailed, and pulls in references to several different areas of research that show the same thing (most of them items that have been in the news in the past year). Short and long is: weight (fat) loss is when total calories consumed is less than the total burned. Exercise makes us hungry, so we eat more. It is noted in the article that people eat more than strictly necessary to offset the calories burned, and that, moreover, the exercise may depress other activity throughout the day.

I would guess that the former phenomenon is due to speed: when we are hungry we tend to eat faster, which can lead to eating more as we outrun the signals that would say we've been sated. The latter, I'm not entirely sure I buy. I suppose it depends on how extreme the exercise is. I do sit more still when I have done a hard workout, but I also move more briskly the next day. I am more bouncy when I have exercised the evening before, rather than less, and I feel better rested as well. This could mean that I have had a more restful sleep that was more still than normal and burned fewer calories, or it could be because the increased metabolism is showing itself, or it could be mental: exercise leads to less guilt which makes me feel brighter and more energetic.

Really, though, there is a reason that it is DIET and exercise. That first word is important. You can lose weight (fat) without exercise, but not without diet. No matter how much one exercises it is possible to eat more to offset. The body must burn calories to survive, however, so an appropriate diet can always lead to consuming less than the body burns.

It is hard to know how many calories we actually burn or how many calories we really eat. Friday breakfast at work means I may eat a couple donuts, half a muffin and a bagel with cream cheese. My normal breakfast is a bowl of cereal with some fruit or a pb&j on toast. I've no idea what the calorie difference is, but I know that if I take an extra long walk with my dog and do half an hour of weights it will offset some portion of that.