Updated

After eating only McDonald’s for three months, Iowa science teacher John Cisna lost 37 pounds and saw his cholesterol level drop significantly, Time.com reported.

No, this wasn’t another documentary experiment like 2004’s Super Size Me – it was a school science experiment.

The now-170 pound man ate a 2,000-calorie daily diet designed by his students. The diet aimed to stay within recommended allowances of nutrients like carbohydrates and fat calories.

Cisna also walked 45 minutes daily during the course of his experiment.

“It’s our choices that make us fat,” Cisna told local TV station KCCI. “Not McDonald’s.”

Click for more from Time.com.