Over time, abnormal blood fats can contribute to atherosclerosis – the buildup of fatty deposits in arteries. Atherosclerosis increases the risk of coronary artery disease and stroke. Triglycerides and cholesterol are the two primary concerns. Triglycerides are the form in which most fat exists in food as well as in the body. There are metabolic conditions that may cause unhealthy levels of circulating fats, but such conditions are most often closely related to diet, lack of exercise and other lifestyle factors.