Eating a heavy meal trigger a heart attack, especially in people who already have heart disease, researchers said in a study released this week at the annual meeting of the American Heart Association. The study found heart attack risk jumped four times in the two hours after a large meal. "A very large meal may start the whole process" of a heart attack, said Dr. Francisco Lopez-Jimenez, a cardiologist at Brigham and Women's Hospital in Boston. He and colleagues interviewed nearly 2,000 patients shortly after they had heart attacks. The researchers asked patients if they had what they considered a "heavy meal" before the attack. The team did not record exactly what patients ate. Of those patients, 158 reported having an unusually large meal during the 26 hours before the attack. Twenty-five patients had the meal in the two hours before the attack. The scientists suggest that fatty meals could impair function of the endothelium, the inner layer of the arteries and that eating and digesting food boosts blood levels of hormones that raise blood pressure and heart rate. However they stressed that more research was required in order to determine which types of food might provoke heart attacks.