Comment by tom-thistime
3 years ago
Yes. And no. Bro science is more or less useless. But the article isn't super useful either. Calories burned are "adjusted for nonfat body mass." Adjusted how?
Fat stores energy. Food adds energy. Exercise uses energy. Those aren't "myths." The article (not talking about the scientist) is very difficult to understand, but it seems to come down on the "myth" side of that dilemma. Mostly. Kind of.
When you do the math, your body turns out to be extremely efficient. Two full hours of very hard exercise burns the equivalent of one average sized lunch meal.
Skipping meals/cutting calories is, by far, the easiest way to lose weight.
Let's get specific.
Maybe your suggestion might be a cataclysmic -1000 calories per day, either by (a) skipping a large lunch completely and not changing exercise, or (b) by doing those two hours of hard exercise and not changing diet. That person will tend to lose around two pounds a week either way over the long term. (Of course I don't really know what numbers you have in mind.)
But losing two pounds a week is insane.
So let's look at safer, more normal behavior. Call it -300 calories per day: either cutting diet by a medium order of fries each day (and keeping exercise fixed) or doing 40 minutes of moderate exercise (and keeping diet fixed). Then the person will tend to lose a pound about every 12 days over the long term. That is still rapid weight loss either way.
If the same person starts riding a bike 40 minutes a day but doesn't count calories, the results could be anything. They could easily put on weight. Who knows?
> So let's look at safer, more normal behavior. Call it -300 calories per day: either cutting diet by a medium order of fries each day (and keeping exercise fixed) or doing 40 minutes of moderate exercise (and keeping diet fixed).
That's not how it works though, and the article we are discussing here is hinting at that. The mechanisms are very complex. Going for a run for 40 min that "burns" 300 calories versus not going on that run won't create a calorie deficit of 300 calories. Because "everything else equal" is never going to happen.
There could be tons of effects happening to offset this. Eating more? Eating subtly different things? Eating it in different ways that impact nutrient uptake? More efficient nutrient uptake even when eating the same things in the same way at the same time? Changing patterns of movement that now use less energy? Change in overall metabolism (body temperature, body movements, ...)? Less stress, saving energy? ...? This is a very complex topic and "calories in versus calories out" is just not cutting it. And that's what the article is about. It's an approximation, but a so coarse one that it's barely usable for anything.
It's a popular science article. What did you expect? If you want all the details, read the actual published studies. For the general public, scientists need to simplify things.
I'd expect them not to call ordinary long-accepted facts "myths" without some kind of coherent explanation. That isn't simplification.
Which "facts" does the article call "myths"? The word "myth" exists twice in it, one of which is in the heading.
That's just part of phrasing everything in catchy popular science terms. Apparently, if you don't do that, then nobody is going to read your article as it reads too boring. (I also find that sad.)
The "train yourself out of obesity" idea that one of the interviewed scientists calls "zombie idea" is not an "ordinary long-accepted fact". Maybe in bro science circles, where obese people are generally just regarded as lazy who just don't get their act together, but that's now how actual medical experts think about this.
The article is another piece in the puzzle of trying to understand how things work. It's not a "myth buster".