"Eating McDonald's for breakfast, lunch, and dinner probably saved my life.”

That’s what John Cisna, a science teacher from Iowa, says in his latest book, chronicling his success in losing weight on a McDonald’s diet.

According to local news station KCCI 8, Cisna first thought of the unique diet after watching the popular 2004 documentary “Supersize Me,” which featured a man who ate at McDonald’s exclusively for one month. The man claimed his health deteriorated significantly as a result.

Cisna decided to put the documentary to the challenge.

Together with a team of students, he filmed his own amateur documentary as he ate McDonald’s for breakfast lunch and dinner for 90 days. There was one catch: he had a strict nutritional limitation of 2,000 calories and tried to stay close to the recommended dietary allowances for other nutrients, such as proteins, cholesterol and carbohydrates.

And no, Cisna didn’t eat McDonald’s salad for three months.

"So this isn't something where you say 'well he went to McDonalds and he only had the salads. No, I had the Big Macs, the quarter pounders with cheese.  I had sundaes, I had ice cream cones," he said.

Here’s a look at what he would eat on a typical day:

  • Breakfast: Two Egg White Delights, a bowl of maple oatmeal and a bottle of 1% milk
  • Lunch: Salad
  • Dinner: A Value Meal with fries.

Cisna also incorporated 45 minutes of walking into his daily routine.

By the end of the experiment, Cisna had lost 37 pounds. He went on to lose another 24 pounds.

The moral of Cisna’s story isn’t to eat more at McDonald’s. Instead, Cisna points to paying attention to your daily nutrition and what you eat.

"The point behind this documentary is, ‘Hey, it's (a) choice. We all have choices. It's our choices that make us fat not McDonald's," he said.

Cisna’s book, “My McDonald’s Diet,” is on sale now at Amazon.com. Click here to read more.  

Of course, Cisna isn’t the first person to lose weight on a McDonald’s diet. Another man, Lloyd Brombach, lose 100 pounds and became a multi-sport athlete while eating McDonald’s every day. Click here to watch a documentary on Brombach’s story.