In a study, children were exposed to 60 images of food logos, such as the McDonald's arches, 60 nonfood logos like the Nike swoosh and 60 blurred images. Reuters

McDonald's will put apples in every Happy Meal as part of a new better-nutrition health initiative and reduce the serving of fries to a half order.

The world's leading fast-food chain will add apples to happy meals among other healthy initiatives in response to customer desires, the company says.

Already McDonald's was offering a choice of apples or fries with Happy Meals, but only 11 percent of customers were choosing apples, the company says. In response, apples will become standard in Happy Meals in early 2012.

McDonald's will include in every Happy Meal a half order of apples and a half order of fries.

"We've been in the nutrition game for over 30 years in providing nutrition information to our customers," said Cindy Goody, McDonald's senior director of nutrition, in an interview with the Associated Press. "Now what we're doing is we're adding more food groups...creating nutritional awareness."

With the new program, McDonald's is also pledging to reduce sugars, saturated fats and calories through "varied portion sizes, reformulations and innovations" by 2020. The company did not provide specific details.

By 2015, McDonald's says it will also reduce sodium in its food items by 15 percent.

McDonald's further says it will launch a new mobile app focused on nutrition information, while also sending McDonald's USA president Jan Fields and others company executives on a "listening tour" this August to hear suggestions from parents and other nutrition experts throughout the country.

McDonald's will also launch a new online forum for parents based upon nutrition.

But the biggest change customers will notice at first will be the change with the popular Happy Meal. Traditionally, fries have been standard fare with the toy-oriented child's meal. Now, they'll only get a half order of fries. If they want a full order, that will come extra, as standard operation will include a half serving of apples and a half serving of fries.