"What we're looking at here is reducing the trans fats in the oil," says McLellan.
And how much better does that make these french fries than, say, the ones you get at McDonald's?
"Well of course the ultimate is when you take one and you actually taste it," says McLellan, as he reaches for a fry. "That's when you know."
As CBS News Correspondent Cynthia Bowers reports, McLellan is trying to find a way to get rid of trans fats: the deadliest kinds because they raise bad and lower good cholesterol levels. So far, no one's found a way to get trans fats or saturated fats out of fast foods without sacrificing taste.
The food industry is intent on finding ways to take the fat out of fast, but meanwhile, it's pushing health - any way it can.
They're trying salads and baked potatoes, lower fat sandwiches and even low fat pizzas to keep the customers coming.
At McDonald's, there's a happy meal for adults on the way.
You get salad, water and a step-o-meter to get you to exercise.
Part of the push comes from a new government requirement to label trans fats, starting in 2006. Snack food giant Frito Lay wants to get a jump on the competition.
"Twenty percent of the snacks we sell today fall into the category of what we call "better for you snacks," says Rocco Papalia, senior vice president of technology for Frito-Lay.
Better means no trans fat and less saturated fats in new versions of its famous chips.
"This has been a huge success for us this year," says Papalia.
Doritos, Cheetos, even that old standby, the Lays potato chip, now come in a staggering number of healthier choices.
"We have potato chips that are 0 grams of fat, 1 gram of fat, 3 grams of fat, 7 grams of fat, 8 grams of fat, 10 grams of fat," says Papalia.
"They are reading the tea leaves as well as everyone else," says McLellan. "These companies would not be in business if they did not listen to the consumer."
Fast food companies are offering more choices, but a salad might have as many calories as a burger if you ladle on the dressing. And fries without fat? Not yet.
"It's the holy grail," says McLellan. "In the end you must produce a food that is good for us, healthy for us and delicious."
Whatever the benefits of lower fat foods, they'll still have to match those original fast and fatty flavors in the only taste test that counts.