Cholesterol production in human body

20 mg of additional cholesterol is produced for each excess kg. of body adipose tissue, which is then excreted in bile. 


This fact obtained from Obesity review course at OMA in Washington DC.  2015


"A human male weighing 68 kg (150 lb) normally synthesises about 1 g (1,000 mg) per day, and his body contains about 35 g, mostly contained within the cell membranes.
Most ingested cholesterol is esterified, and esterified cholesterol is poorly absorbed.
 The body also compensates for any absorption of additional cholesterol by reducing cholesterol synthesis.^[10] 
For these reasons, seven to ten hours after ingestion, cholesterol will show little, if any, effect on total body cholesterol content or concentrations of cholesterol in the blood. However, during the first seven hours after ingestion of cholesterol, the levels significantly increase.^[11]
Cholesterol is recycled. The liver excretes it in a non-esterified form (via bile) into the digestive tract. 
Typically, about 50% of the excreted cholesterol is reabsorbed by the small bowel back into the bloodstream.
Biosynthesis of cholesterol is directly regulated by the cholesterol levels present, though the homeostatic mechanisms involved are only partly understood. 
A higher intake from food leads to a net decrease in endogenous production, whereas lower intake from food has the opposite effect.
 The main regulatory mechanism is the sensing of intracellular cholesterol in the endoplasmic reticulum by the protein SREBP (sterol regulatory element-binding protein 1 and 2).^[39]  
Cholesterol synthesis can also be turned off when cholesterol levels are high. HMG-CoA reductase contains both a cytosolic domain (responsible for its catalytic function) and a membrane domain.
Every day, up to 1 g of cholesterol enters the colon. 
This cholesterol originates from the diet, bile, and desquamated intestinal cells, and can be metabolized by the colonic bacteria. Cholesterol is converted mainly into coprostanol, a nonabsorbable sterol that is excreted in the feces. 
A cholesterol-reducing bacterium origin has been isolated from human feces."
Quote from Wiki