"The complaint was filed in 2002 by four children and their parents, who alleged that between 1985 and 2002, the minors became obese and suffered other adverse health effects, such as coronary heart disease, pediatric diabetes, and high blood pressure after consuming McDonald’s foods. The suit argued that McDonald’s engaged in a deceptive marketing scheme to mislead consumers into falsely believing that its food products – such as Filet-O-Fish, hamburgers and french fries, and Chicken McNuggets – were healthy."

Of course, from the perspective of you and I, it is a bit much to believe that the obese plaintiffs and their children had not the capacity to determine a better meal regimen for themselves than Chicken McNuggets and Happy Meals.  
"In the latest ruling, the court refused to grant class certification or to certify an issue class to determine whether the defendant was liable. The plaintiffs’ claims would require “individualized inquiries…to determine whether each plaintiff suffered injury as a result of being deceived by [McDonald’s] allegedly misleading representations,” Judge Pogue wrote. “Because plaintiffs have failed to present specific evidence of a sufficiently numerous class of individuals who were both exposed to [McDonald’s] allegedly deceptive marketing scheme and have subsequently suffered from the same adverse medical conditions as those alleged by plaintiffs to have been the result of their exposure,” he ruled that class certification was inappropriate."

 In the words of McDonald's corporate office,  "I'm Lovin' It"
"The presence of medical conditions such as obesity or high cholesterol “depends heavily on a range of factors unique to each individual,” the court said.  The court said individualized inquiries were required to rule out various other factors, such as the level of regular physical activity in which each plaintiff engaged."
Individual responsibility is a major aspect of living in a free society.  The tendency for people to blame the results of their own choices to others has become an all too familiar occurrence.  Though not ruling on that basis, the court nevertheless has done well here.  Now each plaintiff will have to prove the causal relationship between their eating of Chicken McNuggets and his or her resulting health issue, excluding of course other possible factors that might reasonably contribute to their health problems.

If they took their kids to eat at McDonalds multiple times a week, how likely is it that discipline was exercised in any of their other lifestyle choices?