Oops, it happened again. McDonald's employee resources website is giving out even more odd advice for workers. This time, it's about the industry it helped make ubiquitous—fast food. "Fast foods are quick, reasonably priced, and readily available alternatives to home cooking. While convenient and economical for a busy lifestyle, fast foods are typically high in calories, fat, saturated fat, sugar, and salt and may put people at risk for becoming overweight," reads one post on the site, which includes a picture of a hamburger and fries, two items that the fast-food giant specializes in selling.

Another post labels a meal with a cheeseburger and fries as the "unhealthy choice" and one with a submarine sandwich and salad as the "healthier choice," noting that it's more of a challenge to eat healthy when visiting a fast-food place.

A separate post writes "it is hard to eat a healthy diet when you eat at fast-food restaurants often," adding that large portions make it easy to overeat. The site also advises people to limit how many fries they eat. (Read more: Recession's over ... so who forgot to tell diners?) "In general, people with high blood pressure, diabetes, and heart disease must be very careful about choosing fast food because of its high fat, salt, and sugar levels," the post said, adding that items from fast-food places are "almost always high" in calories, fat, sugar and salt.

(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.

