Karli Vaughn, 17, Whitney Webb, 15, and Courtney Carswell, 16, (left to right) eat free pancakes at the International house of Pancakes (IHOP) in Santa Monica during National Pancake Day on Tuesday February 28, 2012. National Pancake Day dates back several centuries to when the English prepped for fasting during Lent. Strict rules prohibited the eating of all dairy products during Lent, so pancakes were made to use up the supply of eggs, milk, butter and other dairy products, hence the name Pancake Tuesday, or Shrove Tuesday. IHOP served 4 million free pancakes on National Pancake Day . All of the free pancakes served on National Pancake Day would have created a stack more than 31.5 miles high. Since the inception of National Pancake Day in 2006, IHOP has raised more than $5.35 million and given away more than 10.1 million pancakes to support charities in the communities in which it operates. National Pancake Day is IHOP’s largest one-day event in the company’s 54-year history.