Oh the science is bad in this one!
Let get this straight. Fat will store itself with tremendous efficiency in the absence of insulin. I know shock horror! The hormone known as ASP (Acylation Stimulating Protein) is secreted by the adipocytes when chylomicrons (package triglyceride in the blood) are dected, and then packages them (the triglyceride) away into the adipocyte (simplictic but will do for this example). The body also absorbs most of what you eat with tremendous efficiency too, there's no way we would have evolved to excrete ingested foods / energy, so the conjecture that we'll poop out excess protein and carbs is pure myth.
"Acylation Stimulating Protein (ASP) is a small (mol wt 14,000), basic (pI 9.0) protein present in human plasma. When examined in vitro with normal human cultured skin fibroblasts and adipocytes, ASP appears to be the most potent stimulant of triglyceride synthesis yet described. In this study, a competitive ELISA assay for ASP has been developed using immunospecific polyclonal antibodies, and ASP levels have been measured in seven normal subjects. Following an oral fat load, a sustained significant increase in ASP occurs, whereas after an oral glucose load, ASP levels do not change significantly. These responses are entirely opposite to those of insulin, which rises sharply but transiently after an oral glucose load but is unchanged after an oral fat load. Both the fasting and peak ASP levels were significantly related to the postprandial lipemia. These data provide the first in vivo evidence that Acylation Stimulating Protein may play an important physiological role in the normal response to an oral fat load."
This explains quite well how you CAN get fat on a low carb diet. Unfortuantely contrary to Taubes calories DO matter.
The examples of people posting studies of subjects losing weight on an ad-lib low carb high fat diet are usually down to eating less calories overall than they actually thought (Fat and Protein are very hunger curbing). Explain to me why there are thousands of low carb forums with hundreds of overweight people posting on them? Yes I advocate the PB way of eating, but I'm afraid calories do matter ultimately.