In recent years, McDonald's has changed the choices for Happy Meals to allow customers to swap out soda for low-fat milk, or fries for apples.
"You can get a simple plain hamburger with low-fat milk and fresh apple slices, and that's actually a meal that fits in with dietary guidelines. That's a reasonable choice," said Ayoob.
Ultimately, Ayoob said it "becomes a parenting issue of who is in charge. My parents never had any difficulty telling me no."
In a CSPI letter to McDonald's obtained by ABC News, CSPI acknowledged that McDonald's pledged to "advertise only Happy Meals that meet McDonald's nutrition standards for children" through the Children's Food and Beverage Advertising Initiative of the Council of Better Business Bureaus.
However, the letter also includes the results from a small CSPI research study of 44 McDonald's outlets in which CSPI found "in response to a request for a hamburger Happy Meal, the McDonald's employee, without asking customers which side dish they wanted, provided fries 93 percent of the time."
When asked why CSPI singled out McDonald's from any other restaurant that appeals to children with coloring books or playgrounds, Jacobson said the size of the marketing reach was what mattered
"McDonald's is so much bigger than any other restaurant, so much more aggressive in marketing its products to kids, and the toy is the centerpiece of its marketing," Jacobson told ABC News. "That's why every popular film that comes out, McDonald's is there to take advantage of the characters to entice kids into their restaurants. I don't know of any other restaurant company that does something of the same magnitude that McDonald's is [doing]."