I wrote about Gary Taubes, the science journalist and author of Good Calories, Bad Calories, in this post two weeks ago.

I'll concede up front that Taubes is smarter than me, has been writing about nutrition far longer than I have, and bases his views on research so deep that I would drown in it.

That said, I'm going to disagree with him about the premise of this excerpt from his new book.

The short version: Exercise makes us fat.

The long version is pretty much the same: Your body has mechanisms that prevent you from falling out of homeostasis, meaning that you eat and store fat to compensate for any fat you burn off during exercise.

I'll let him explain it:

Everybody reading this can probably spot the logical fallacy in the part I highlighted. If we're comparing the lumberjack with the tailor, who's leaner? Whose body has more muscle mass, and whose body has more fat? Which one is at higher risk for heart disease, diabetes, and other afflictions of the fat and sedentary?

Going deeper: What's wrong with someone eating more to compensate for exercising more? The net result will almost certainly be a leaner body, no matter how much that body weighs.

The reason is a phenomenon called energy flux, which I wrote about in a magazine article almost four years ago, and which I explored in some detail in The New Rules of Lifting and The New Rules of Lifting for Women.

Energy flux is important because eating more increases our metabolic rate. We all know that a percentage of the calories we consume are burned during digestion (even if this basic fact is all but ignored by most mainstream dietary advice). But there also seems to be a synergistic effect of exercising more and eating more that increases metabolism beyond what either could do on its own.

That's why a lumberjack can eat twice as much as a tailor, but still be leaner. He's not necessarily burning off thousands of calories more than the guy with the sedentary job. The combination of food and exercise gives him a metabolic rate that's much faster than the tailor's, which is why he's going to be much leaner, even if the two guys weigh the same.

Which is not to say that what people eat, and how much they eat, is unimportant. People in my field have shown the importance of timing meals to multiply the benefits of workouts, and Taubes himself has reported on the vastly different metabolic effects of different types of nutrients.

There's also the issue of genetics. Consider this:

For my money, the key word there is "nonathletes." If you put me into a marathon-training program, all I'd get out of it would be a lifetime of orthopedic problems. I might even end up fatter. Why? Because my body isn't suited to endurance exercise. But you could put me on a powerlifting program and I'd probably get leaner. Why? Because my body responds quickly to strength training, and easily partitions nutrients to my muscles and away from my fat deposits.

Now let's get back to energy flux: If you took trained marathoners and forced them to stop running for a designated period, they'd almost certainly get fatter, even if they were eating fewer calories to compensate for the loss of exercise. Their metabolic rates would slow down, which means that more of the calories they eat would be treated as excess energy, and stored in their fat cells for future use.

So while nonathletes don't necessarily get lean with athletic training for a sport they're ill-suited to pursue, athletes in those sports would certainly get fat if they stopped training for them.

I guess the real point of all this is that weight control is a three-step process: You have to figure out the right type of calories for your genetics, the right amount of calories for your activity level, and the right type of exercise for your body, your schedule, and your interests. There's no single solution that works for everybody, and I wish all of us would quit pretending that there is or should be.

Monday blog workout

• This story about HDL cholesterol makes a good companion piece to Taubes' book excerpt. It says that cholesterol-lowering drugs can reduce heart-attack and stroke risk by 40 to 50 percent, but there's no simple and easy way to raise HDL, the "good" cholesterol, which would reduce that risk even more. The researchers wring their hands in despair over the lack of a pill to raise HDL, and note that the only thing that really works is to "become lean and become very active." But, as we all know, that's much easier said than done.
• Fortunately, there's a much easier way to increase HDL, which researchers on the hunt for a pharmacological solution will always overlook. As my friends Adam Campbell and Jeff Volek report in their new book, TNT Diet, a low-carb diet increases HDL cholesterol. In Volek's studies at the University of Connecticut, HDL goes up an average of 13 percent on low-carb diets. LDL may increase, decrease, or stay the same, but the bottom line is that "HDL increases significantly more than LDL, [which means] your risk of heart disease goes down."