Final answer:
A diet high in saturated and trans-fat causes the liver to produce higher levels of LDL, or 'bad' cholesterol, which can contribute to heart disease. Trans fats are especially harmful as they also lower 'good' cholesterol and promote inflammation.
Step-by-step explanation:
When eating a diet high in saturated and trans-fat, the liver produces even more low-density lipoproteins (LDL), or "bad" cholesterol, causing a problem. Trans fat, often found in processed foods such as margarine, cookies, and fried items, is particularly harmful. It not only increases LDL cholesterol but also decreases high-density lipoproteins (HDL), known as "good" cholesterol, and promotes inflammation, which can lead to coronary heart disease.
The elevation of plasma free fatty acids from these fats leads to increased VLDL secretion by the liver, which contributes additional triglycerol and cholesterol to the bloodstream. Due to their detrimental effects on heart health, many fast food restaurants and food producers have recently decreased or banned the use of trans fats, and food labeling regulations now require displaying trans fat content.