Teacher Loses Weight After Eating Only McDonald's for 3 Months Remember the 2004 documentary Super Size Me and its blatant lack of a twist ending? Guy eats only highly processed, high-fat McDonald's food for one month. Guy's health deteriorates. The end. Science teacher John Cisna tried out a similar experiment, but saw drastically different results. After eating nothing but McDonald's for three months, the Iowa man lost 37 pounds and saw his cholesterol level drop significantly, local TV station KCCI reports. Cisna enlisted his students to help him plan out a 2,000-calorie daily diet plan consisting only of food sold by the fast food giant. They also tried not to exceed recommended allowances of nutrients like carbohydrates, proteins, fat calories and cholesterol. For breakfast, Cisna typically ate two egg white delights, a bowl of maple oatmeal and 1 percent milk. For lunch, he'd usually opt for a salad. And for dinner he'd order a more traditional value meal, including items like Big Macs, ice creams and sundaes. After Cisna told the owner of the local franchise about the experiment, he was so interested that he agreed to provide all the items free of charge. During the experiment, Cisna walked for 45 minutes every day, and by the 90th day he reported that his weight had dropped down to 170 pounds from 249. He said he was able to get healthier simply because he made smart choices. "It's our choices that make us fat," Cisna told KCCI. "Not McDonald's."