OK ... I'm about at my wits end with some of these discussions about the net. It's as if basic logic is not enough for some folks. The scientific method for testing hypotheses is not difficult folks. You don't need a genius IQ or even a high school diploma to "get it".
Let's say, hypothetically that based on my observations, I propose A causes Z. Others propose B, C or LMNOP cause Z. I design my experiment. Realistically it's impossible to control for all possible other factors -- called confounding variables or simply confounders -- but I make a good faith effort to do so. In other words, I consider that B or C etc. may be the actual cause and merely occur concurrently with my beloved "A".
And so I control. In my experiment I have a study group (aka treatment group) where I vary "A", and my control group. My control group will be as like my study group in other variables as possible. Therefore when I see a statistical difference in Z in my study group as compared to the controls, this is convincing evidence that my manipulation of A was indeed the cause. True, we cannot rule out that there was a confounder "Q" I did not account for, but good scientists make it a habit to control for at least the obvious confounders.
So ... let's say I say A causes B. And someone else, say George Thibideaux, aka GT, says C causes B. I design my study. I randomly assign subjects meeting certain criteria to two groups. I then vary A in my study group while keeping C the same between the two. I see a change in B. This does not "prove" A causes B, but it is consistent with the hypothesis that A causes B. Further, if I repeat similar experiments (always keeping C constant) enough times, and the expected result for my hypothesis occurs time and again, this becomes convincing evidence that, indeed, A causes B.
I'm sure everyone would agree with the above. If you do not, there really is no reason to read on because you are so hopelessly biased because you know where I'm going with this that you cannot accept basic science.
Let's put dietary "stuff" to my ABC's. Let's say "I" am actually Gary Taubes. Gary Taubes claims carbohydrates, and solely carbohydrates "A", irrespective of calories "C" (yes, that's what he now claims) causes us to get fat. So his "A" is carbs (through the virtue of insulin stimulation) and his "B" is weight gain. Now some formerly bunny-eared anonymous blogger, aka your's truly claims that it is "C" that leads to "B", that "C" being caloric surplus irrespective of macronutrient composition.
We test this. How should GT test his? By controlling for calories. If you do not, it's a moot point and I'm willing to bet that most if not all of Andreas' 14 studies (to zero? Really, you're serious?) did not control, let alone carefully, for calories. The studies that control calories demonstrate no weight loss with even dramatic changes in macronutrient composition. On the other hand, if I want to test my hypothesis, I can control for carbs and alter calories. Guess what. The data support that every time. PERIOD.