(Read more: Restaurants' big bet to get you to spend more)
The posts appear to be content provided by a third-party vendor.
McDonald's defended the posting in a statement issued Monday afternoon.
"Portions of this website continue to be taken entirelyout of context," McDonald's statement said. "This website provides useful information from respected third-parties about many topics, among them health and wellness. It also includes information from experts about healthy eating and making balanced choices. McDonald's agrees with this advice."
The company also noted that it has added healthier menu options in recent years, including "oatmeal, grilled chicken, egg whites and real-fruit smoothies."
It was the latest in a series of gaffes involving the site.
Last month, the company detailed tipping advice for workers, many of whom make around minimum wage. It listed pricey suggestions for tipping au pairs, personal fitness trainers and pool cleaners from etiquette maven Emily Post—advice it removed after a CNBC inquiry. McDonald's told CNBC the post was third-party material and said it would "continue to review the resource and will ask the vendor to make changes as needed."
(Read more: McDonald's out-of-touch tipping advice)
Although the McResource Line is nominally a site for employees, it is accessible via a registration process that does not actually verify employee credentials, meaning anyone can register for it by providing a username and email address and selecting a McDonald's region.
This advice is available on McDonald's site at a time when the fast-food giant has been working hard to distance itself from fast-food's reputation as bad for you, adding more fruits and vegetables and fat-free chocolate milk.
At its annual shareholder meeting in late May, McDonald's CEO Don Thompson defended his company's food, saying, "We don't sell junk food."
McDonald's also saw backlash after it advised employees to get out of holiday debt by returning unopened purchases and after it published a budget guide that included no money for heat and $20 a month for health care.