Fat, Inflammation and Atherosclerosis
Not to hammer on the point too much, but excess body fat held over the years causes chronic inflammation, which enrages your immune system, which leads to atherosclerosis, which tends to kill you abruptly and without warning. All very avoidable. To make matters worse, excess fat - or rather all the food you ate in order to create the excess fat - creates a feedback mechanism that leads to insulin resistance and diabetes, and this makes the atherosclerosis-generation process run faster: "Experts once believed that atherosclerosis, or hardening of the arteries, developed when too much cholesterol clogged arteries with fatty deposits called plaques. When blood vessels became completely blocked, heart attacks and strokes occurred. Today most agree that the reaction of the body's immune system to fatty build-up, more than the build-up itself, creates heart attack risk. Immune cells traveling with the blood mistake fatty deposits for intruders, akin to bacteria, home in on them, and attack. This causes inflammation that makes plaques more likely to swell, rupture and cut off blood flow. ... In part because diabetes increases atherosclerosis-related inflammation, diabetic patients are twice as likely to have a heart attack or stroke. ... Inflammation is blood vessels is one of the main drivers of atherosclerosis, and diabetes makes it much worse."
Link: http://www.eurekalert.org/pub_releases/2008-03/uorm-sic031308.php