Save Your Heart: Walk Before the Big Meal Exercise 12 hours before eating lessens spike in dangerous fats By Rob Quinn, Newser Staff Posted Nov 24, 2011 3:01 AM CST 3 comments Comments A huge dinner can cause more than just a "food coma," researchers warn. (Shutterstock) (Newser) – The best time to walk off a gut-busting Thanksgiving dinner is at least 12 hours before you eat it, researchers say. Studies have found that light exercise, like a half-hour walk, done 12 to 16 hours before a big meal significantly reduces the post-meal spike in a type of fat called triglycerides, the Wall Street Journal reports. Triglycerides penetrate arterial walls easily and elevated levels of them have been linked to a much higher heart attack risk. It's not clear why there is such a long delay between the exercise and the benefit but exercise induces cellular changes that can last for as long as 48 hours, say researchers, who stress that being consistently active is the best way to keep down levels of dangerous fats. "Those people wishing to start an exercise regimen can see beneficial effects on postprandial lipids with just one session," says the director of Baylor University's Center for Healthy Living.