Hi PERKDOUG. Your hypothesis is incomplete - you do not address chylomicron's which transport dietary triglycerides and cholesterol. Also as I understand it HDL does not get destroyed in the manufacture of VLDL, which is synthesized de novo by the liver, rather it donates apoC which matures chylomicrons and VLDL.
These however are small points - as any hypothesis needs real data from humans, just because something is theoretically feasible doesn't mean that it occurs for real. Your fructose hypothesis is also problematic - due to lack of evidence
I looked through the first half dozen pubmed studies for evidence that your hypothesis is correct, only one supported your hypothesis the rest did not.
There is evidence that low carb diets in individuals with insulin resistance, decrease triglycerides, raise HDL, and improve glycemic control - how reliable these studies are is another matter, as I am aware that when cochrane looked at glycemic control they were unable to show any difference between low and high fat diets.
Low carb diets also raise rather than lower LDL - which is in the reverse direction suggested by your hypothesis.
low fat diets are better at decreasing total cholesterol, and lowering LDL, which again does not support your hypothesis.
pubmed link to a review included below
An update on low-carbohydrate, high-protein diets. [Curr Opin Gastroenterol. 2006] - PubMed Result
