How is it a risk factor?
Lack of Exercise
People who are aerobically fit have larger, strong hearts with clearer and more elastic arteries which means that the heart does not need to deliver as many beats to deliver the same amount of blood than people who are less aerobically fit, therefore this saves more heart beats every year and so it won't wear out and tear the heart as easily.
For the people who are overweight, there's an extra strain put of their heart as the heart has to pump blood to all the extra fatty tissues around the body which is very heavy work which can wear the heart out and tear the heart easily.
High Levels of fat and cholesterol in your blood
When someone eats a lot of fatty and high cholesterol foods such as dairy products, greasy takeaway food and red meat, the fat and cholesterol gets absorbed into their blood.
For people who have more fat and cholesterol in their blood, it is more likely for them to get cardiovascular disease because the fat and cholesterol will stick to the inside of their arteries; this then leads to atherosclerosis as the layer of plaque gradually builds up.
High blood pressure
Blood pressure is the measure of the pressure in the arteries when blood is squeezed into the arteries from the heart. When someone has high blood pressure, their arteries become hardened by atherosclerosis which will increase the chances of a blockage that causes a heart attack or a stroke (which are one of the effects of cardiovascular disease).
Smoking deposits cholesterol in the arteries which may damage artery walls. Smoking also reduces the level of high-density lipoproteins (or HDL) in your blood. HDL is the "good" cholesterol which clears the "bad"...