An Iowa high school science teacher who ate all but one of his meals at McDonald's for six months says he's lighter and healthier than before starting his weight-loss plan.
John Cisna, from Colo, Iowa, told the TODAY
show he lost 56 pounds on the diet, lowered his cholesterol, and lost a total of 21 inches off his chest, waist and hips while dining only at the fast food emporium.
Cisna has documented his experience in the new book, "My McDonald's Diet."
He told TODAY he followed a 2,000-calorie diet, using the daily recommended allowances for carbohydrates, proteins, sugar and fat; and he walked 45 minutes a day.
When the experiment began on Sept. 15, the 6-foot-tall teacher weighed 280 pounds, amounting to a body mass index (BMI) of 38, which is considered obese. Now at 224 pounds, his BMI is down to 30 -- still obese but very close to the overweight category.
He also said his total cholesterol dropped from 249 to 190, including a 25 percent decrease in his LDL "bad" cholesterol.
Cisna said the only time he had a problem sticking to his diet was one occasion when he was waiting for a flight at LaGuardia Airport after a long day and couldn't find a McDonald's.
"I was starving," Cisna recalled. "In front of God and the whole world, I admit that that night, I had a bag of cashews, an apple and a diet Pepsi, so that's the only time that I have broken from the diet."
Still, nutrition experts have been critical of his approach.
Cisna McDonald's diet is not realistic or reasonable for most people, said Elisa Zied, a registered dietitian nutritionist in New York and author of "Younger Next Week," noting the results have to do with cutting his calorie intake.
But his diet was also likely high in sodium, low in fiber, and not as rich in vitamins and minerals because it lacked a variety of fruits, vegetables, whole grains, and other nutrient-rich foods.