A few bits of research:
People's cholesterol levels react differently to diet depending on their genes, so some crossfitters can eat vast amounts of bacon and their LDL doesn't budge, but not all can.
Elevated LDL with good TG and HDL is common with all low carbers, both in the scientific papers and on low carb forums.
So there are at least 3 factors:
-something about low insulin and reliance on fat metabolism may increase LDL (by weight) in some people, due to increase in particle size; however this would go against the fact that LDL is well established as an independent risk factor (i.e. a high LDL still represents a risk even if the other 2 numbers are good, and treating LDL by itself reduces cardiac events)
-some insulin sensitive people may also be more sensitive to dietary cholesterol (eggs) http://atvb.ahajournals.org/cgi/cont...ract/23/8/1437
-some paleo dieters may be avoiding some of the more useful sources of soluble fibre like apples (and potatoes of course) that they used to eat and eating somewhat more saturated fat in getting their protein requirements
The main problem is that most research is not done on people who exercise and have no other risk factors, and who eat a low carb diet even though they are not overweight or 'dieting'.
However, the fact that this LDL (and TC) increase appears to occur across a proportion of low carbers in general, regardless of the activity level, would seem to imply that it is a phenomenon independent of exercise, and of insulin sensitivity (i.e. there will be some fit people who get heart attacks, although they are relatively rare). The fact that insulin resistance correlates only similarly to LDL in heart attack prediction (The Copenhagen Study) (http://atvb.ahajournals.org/cgi/cont...baha;17/6/1114
) implies LDL should be monitored independently.
I've concluded from reading all this that I may not be in the genetic group of those who can eat saturated fat and cholesterol and keep a low LDL. I'm going to see what happens if I reduce the sat fat somewhat and make a point of getting plenty of soluble fibre when I do eat it.