Just One Meal.
A single fatty meal can cause the heart to beat harder and increase blood pressure. Researchers analyzed the effects of eating a high-fat fast food meal (42 grams of fat) and eating a meal with no more than 1.3 grams of fat. When subjected to a series of standard stress tests, those who ate the high-fat meal saw their blood pressure go up 1.25 to 1.5 times higher than the those who ate the low-fat meal.
Journal of Nutrition, April 2007