Humans have two sources of cholesterol: absorption from ingested food and de novo synthesis by the liver High levels of cholesterol in the blood correlates with cardiovascular disease, but cholesterol is required to regulate membrane fluidity and as a precursor for important molecules like steroids and bile acids. Thus, humans evolved several types of regulation of cholesterol levels. How does the human body compensate for excess consumption of cholesterol in the diet?

Eating a cholesterol-richmeal causes the hypothalamus, the hunger center of the brain, to signal satiety

Excess cholesterol and a lack of ATP inhibit the activity of HMG-CoA reductase in the liver to decrease cholesterol synthesis

Transcription of the HMG-CoA reductase gene decreases in the presence of high intracellular cholesterol

High cholesterol concentrations upregulate the number of serum transport proteins that deliver cholesterol to the liver for degradation.

Adipose cells switch to using cholesterol instead of glucose to produce ATP