I spent a week eating vegetarian fast-food from all the major chains - and it was absolutely terrible

As someone who loves both meat and chain restaurants, I was only partially prepared when I adopted a 100% fast-food diet, with no meat allowed.

After spending a week trying to eat healthy while consuming nothing but fast food, I figured that going vegetarian for five days would be a breeze. I already knew fast-food menus like the back of my hand, and had plenty of vegetarian friends I could consult.

Plus, a growing percentage of the American population has already gone vegetarian. While approximately 3% of the US identifies as vegetarian or vegan, an increasing number are cutting meat from their diet. Between 26% and 41% of Americans report that they cut down on the amount of meat they ate in the past year.

If fast-food chains want to compete with the new wave of trendy fast casuals, they need to appeal to the vegetarian market - including people who want to decrease the amount of meat they eat without cutting it completely from their diet.

So, I became a short-term vegetarian to see which fast-food chains are evolving to meet the meatless needs of consumers.