Equal parts Manx, Irish, French, and English.
Weight-wise I'm very sensitive to carbs on the margin. If I eat a lot of potatoes, my abs are much less well-defined. I have no idea whether this necessarily indicates that I'm less healthy overall with carbs.
As a vegan I ate a carb-heavy low-fat diet of chickpeas, tahini, oatmeal, peanut butter, bananas, hemp protein, potatoes, rice bubbles, cheeseless pizza, fruit, bread, pasta, rice, etc... I felt fine but didn't have well-defined abs even as an intensely-training college athlete.
Switching to Taubesian fat-heavy LC (eggs, meat, milk, canola oil, peanut butter, one slice of bread per day, diet soda, etc.) I lost the visceral fat in a few weeks while doing no deliberate exercise.
I don't believe I had a particularly "deranged metabolism" as I've never been significantly overweight, never had any significant health problems, had always had good medical markers. So my anecdotal experience fits exactly with the most simplified Taubes explanation.