Syndrome X describes people who have low blood levels of the good HDL cholesterol and high blood levels of triglycerides, which puts them at high risk for heart attacks. HDL cholesterol is called the good cholesterol because it carries cholesterol and triglycerides from your blood to your liver before they can form plaques in arteries. Triglycerides are manufactured by your liver from extra food that you take in, primarily from refined carbohydrates which cause a high rise in blood sugar. Excessive amounts of triglycerides cause a condition called fatty liver that interferes with liver function.
Your liver is supposed to remove insulin from your bloodstream after the insulin has done its job of driving sugar from the bloodstream into cells. A fatty liver does not remove insulin as well as it should, so large amounts of insulin accumulate in the bloodstream. Excess insulin affects your brain to make you hungry all the time, causes your liver to manufacture even more fat, causes you to deposit more fat in your belly, and constricts arteries.
People with high blood levels of triglycerides and low levels of the good HDL cholesterol are at high risk for obesity, diabetes and heart attacks. The tendency to develop Syndrome X is genetic but it will not appear if you burn more calories than you take in. If you have this syndrome, you should avoid all refined carbohydrates: foods made with flour, white rice, milled corn, and any type of added sugar. Eat plenty of vegetables and WHOLE grains, and (of course) get plenty of vigorous exercise.