Slenderize Me

(CBS)  In the award-winning documentary film "Super Size Me," filmmaker Morgan Spurlock went on a 30-day diet, eating nothing but McDonald's fare for breakfast, lunch and dinner.

The film made headlines because Spurlock gained a lot of weight and suffered a number of physical ailments.

But now, an Illinois man, Dennis Yohnka, is flipping "Super Size Me" on its stomach: He's lost 40 pounds in 50 days by eating little other than McDonald's salads.

Yohnka says he was tired of weighing 269 pounds, at 6 feet 1 inch. He'd tried all the fad diets, to no avail. Then he realized he could simply modify his regular diet, which included lots of McDonald's hamburgers and fries, and make a healthier choice of salads with chicken, while continuing to eat at his favorite establishment.

Yohnka attributes his success to choosing a plan that was simple and didn't require a lot of change.

He spoke to The Early Show co-anchor Harry Smith while standing in front of his favorite McDonald's, in Crest Hill, Ill.

"Back in January, I wanted to do something special after the holidays," Yohnka told Smith. "I was closing in on 270, man -- that's way too much for me."

He weighed 229 Friday.

Yohnka says he was actually inspired by "Super Size Me."

"I saw the movie," he says, "and I thought, 'Gee, I don't get it. If you make good decisions instead of bad decisions, it's more up to us than it is the food chain or anybody else.' "

So he began eating Cheerios or oatmeal for breakfast, and McDonald's salads with chicken for lunch and dinner. He eventually took a liking to the chain's low-fat dressings as well.

He admits he loves the smell of burgers and fries, and was sometimes tempted, but says he actually wound up getting a bit self-righteous: "I started looking around and going, 'What are you doing with the burger, with the Big Mac here? You could be using the salad like me.' "

Yohnka's goal is to "go through the 220s and into the teens, and if you're going to ask, 'Do I want to be the next Jared?' No. I have a good job. I would arm-wrestle him, though, because I'm still lifting weights," he remarked, referring to the famous weight-loser associated with the Subway fast food chain.

On a more serious note, Yohnka, who's a high school administrator, said, "Part of what this was about for me is to point out to kids, we tell them all the time, you make decisions according to what's in your environment. If you make good decisions, that's how you get ahead. Making bad decisions keeps you somewhere else."

What will he have for his first big splurge when he's off his diet? "I'm surprised at this. …I thought I would run to Ben & Jerry's or whatever. But I'm looking forward to, like, a salmon steak with vegetables, not a baked potato. I can't see myself letting go anymore."