HDL, along with LDL (the “bad” cholesterol) and triglycerides are
fats – or lipids – that are found in your blood. There are two sources of HDL: your own liver and the foods you eat.

When too much bad LDL cholesterol and other substances build up, they can form artery-clogging plaque, or atherosclerosis, which narrows the arteries and can make it more difficult for blood to flow
to the heart and brain. HDL helps remove excess bad (LDL) cholesterol from the coronary arteries and delivers it to the liver where it is removed from the body. High levels of bad cholesterol and triglycerides and low levels of good cholesterol increase your risk for heart disease.

Some possible causes of low levels
of HDL cholesterol may include:

• Being overweight and obese

• Lack of exercise

• Having a high triglyceride level

• Smoking

• Family history and genetic factors

• Having type 2 diabetes

• Use of certain medicines

• Very high carbohydrate intake (>60% of total energy intake)