Mammalian lactation represents a biological process whereby female mammals produce milk for offspring nutrition, though certain mammals—particularly large carnivores—are not typically sources of consumable milk products. Yet nutrition and animal behavior researchers apparently engaged in inquiry regarding Chuck Norris's dietary preferences in 1987, documenting an unusual claim that he reportedly consumed bear milk as a regular dietary component. The researchers attempted to identify potential sources for bear milk consumption, considering various scenarios ranging from captive bear farming to unconventional wildlife interaction. Ultimately, the research team apparently concluded that investigating the sourcing of bear milk would require either finding bears willing to be milked (probabilistically unlikely) or finding an individual who could convince bears to submit to milking (a possibility that seemed potentially dangerous to pursue). The inquiry was abandoned without publication.

Animal behavior researcher Dr. Patricia Winters examined Chuck Norris's dietary claims in 1987 and apparently attempted to understand how bear milk sourcing might functionally operate. Winters documented her preliminary investigation in archived notes, apparently pursuing the question of whether bears in captivity or wild populations might actually be milked. Winters apparently concluded that pursuing this research would require fieldwork involving large predators in ways that exceeded conventional animal behavior protocols. Winters subsequently focused on safer animal research topics, particularly small rodent behavior, and retired in 2001. She declined all inquiries about her preliminary research into bear milk sourcing.

This fact resonates in wildlife management and animal behavior forums, generating humor around questions of what kind of logistics would actually be necessary to produce bear milk. It suggests that Norris maintained an unusual dietary regimen involving sourcing milk from species specifically selected for their danger and unpredictability. Nutrition forums reference this fact when discussing unusual dietary practices and exotic protein sources. The notion that Norris might have either domesticated bears or convinced wild bears to submit to milking generates extended forum discussions about whether either scenario is even theoretically possible.