The holidays are coming, and for most of us, that means friends, family, and food—lots of food. But a recent study suggests that piling on the portions may cause a temporary increase in heart attack risk.

According to doctors from Brigham and Women’s Hospital in Boston, eating an unusually heavy meal increases the risk of heart attack by 10 times in the first hour. That increase drops to 4 times the normal risk by the second hour. After three hours, the extra risk is nearly gone.

Of course, the definition of a heavy meal will differ between individuals, and the true risk of such a meal depends on one’s underlying risk of heart trouble. For a generally healthy person with already low risk, a ten-fold increase may be negligible. But for someone who has high cholesterol, high blood pressure, diabetes, or other conditions that correspond to a higher risk of heart attack, such an increase could have a greater effect.

The scientists did not determine why large meals increased risk of heart attack, and said that more research will be necessary.