Diet
A McDonalds diet - high fat and high salt - will kill you because it clogs the arteries and ups the blood pressure. Every literate person in this country already knows this.
This does not mean that you need to make the rest of your life a misery by forgoing all the foods you like. It does mean that a drift away from McDonalds towards more fresh fruit and veg will improve your chances. Fat content is listed on the packets of most foods and there are some surprises - some foods you might have thought harmless enough turn out to be full of fat.
In practice, drugs account for 90% of the reduction of cholesterol in heart attack survivors but diet has an important psychological function.
A cardiac arrest is normally called a heart attack. ..an attack by an enemy against which you cannot retaliate. Diet is one of the ways you can feel that you are fighting back.
See also
drugs and exercise.