The available studies only show that high fat diets can lead to an increase of LDL particles in the bloodstream but there are two problems with such studies ...
For one LDL isn’t bad per se, LDL providing just transport for triglycerides in the bloodstream and it’s more important what those particles contain. Saturated fat leads to big, fluffy LDL particles which aren’t considered to be a threat.
On the contrary it is sugar that leads to LDL particles that are low density and dangerous. If you’re worried about LDL, it’s much better to cut the sugar and the poly-unsaturated fat.
The second problem with such studies are the common confounders: sugar and PUFAs. Whenever you see negative claims about fat in studies, read the actual study and more often than not you’ll see sucrose or PUFAs being used in the diet of the subjects.
What’s absolutely ridiculous is that excess carbohydrates get converted to saturated fat. Our body only needs about 600 calories per day from carbohydrates, the rest being converted to fat.
It is saturated fat that provides a majority of the daily energy needs, not just in humans, but in all mammals.