Celebrity chef and food activist Jamie Oliver is a man on a mission: to stop the use of what he calls "pink slime," beef scraps no one would choose to eat, reprocessed and repurposed for use in hamburger patties.
It is, he asserts, "not fit for human consumption."
"We're taking a product that would be sold in its cheaper form for dogs and," he says, "after this process, we can give it to humans."
The first salvo in his high-profile food fight was an April 2011 stomach-turning demonstration on his TV show, "Food Revolution," nine months ago.
He washed bits of beef in a solution of ammonia and water -- ammonium hydroxide -- to kill off bacteria, a technique approved by the Food and Drug Administration.
"This is a practice," Oliver says, "that's openly admitted to being in 70 percent of ground beef. That kind of puts it everywhere."
But last week, McDonald's announced it's no longer using the controversial beef. In a statement, the chain said the decision "was not related to any particular event."
Still, Oliver said he's "thrilled."
But, if he considers McDonalds a victory, he'd have to call Los Angeles a loss. City schools rejected his offer for a healthy menu makeover and decided to go it alone.
And student Kevin Albrecht says, "The healthier it gets, the more disgusting it is."
Some can barely describe what "it" is.
Fellow student Marina Sangit said one item is "called a barbecue sandwich, but it looks like an imitation Sloppy Joe."
So, the district keeps trying, testing healthy, "tastier" foods on kids and parents.
But, observes student Cameron Michaels, "Any food (adults say) is good for me, I think I'm not going to like it."
Yet - one student says he likes "the pesoli, the hummus and the water."
Parent Amu Narin agreed, noting, "He's shoveling it in. And I've never seen him eat salad at home."
Like Jamie Oliver, the schools want healthy foods, but they're learning kids will only eat what's good for them, if it tastes good.
To see Bill Whitaker's full report, click on the video in the player above.