NEW YORK » Ronald McDonald is having a midlife crisis.

His floppy shoes, painted-on smile and flaming-red hair might be a harder sell to today’s kids who are trading in their dolls and trucks for manicures and mobile game apps at ever-younger ages. He also seems out of step with McDonald’s Corp.’s new efforts to appeal to adults. The 48-year-old spokesclown has fallen flat in new ads this year, according to Ace Metrix, a group that tracks TV advertising.

And the government is getting strict on marketing unhealthful food to children. That has both marginalized Ronald as more of a mascot than a product pitchman and landed him in the middle of the bigger debate about food makers’ responsibilities in stemming the rise in childhood obesity.

McDonald’s says it is proud of the food it offers and that Ronald teaches children to be active.

Critics say it’s time to hang up the yellow jumper.

A group called Corporate Accountability International plans to ask Ronald to retire at the company’s annual meeting tomorrow. They say Ronald encourages kids to eat junk food, contributing to a rise in childhood obesity and related diseases such as diabetes.

McDonald’s defended Ronald against the group’s attack at last year’s annual meeting and is adamant that it has never considered retiring or even downplaying their smiling mascot.

"It’s totally unfounded," said Marlena Peleo-Lazar, the company’s chief creative officer, who describes Ronald as "a force for good."

Ronald, the world’s most famous clown, had humble beginnings with a paper-cup nose and scraggly blonde wig. First played by Willard Scott in 1963, he dispensed burgers and fries to delighted children and flew around on a magic hamburger. "Goofy and clumsy" is the way McDonald’s describes the early incarnations.