Billed as a modern cannibal tale, “Keep the River on Your Right” is an unconventional documentary about appetite. Inevitably it will be considered alongside the recent and ridiculous “Hannibal” as a movie about the taboo subject of cannibalism. But the comparison should end there.

While “Hannibal” gives us a globetrotting, generally creepy, fictitious old man, “River” offers a globetrotting, occasionally creepy, very real old man. On the surface the films are very similar, but at the core they are opposites. Hannibal’s meal is flesh; Tobias Schneebaum’s is life.

The documentary’s action involves an American film crew’s aggressive persuasion of a reluctant Schneebaum, a 78-year-old gay man with Parkinson’s Disease, to return to both the Peruvian Amazon and the Indonesian jungle. Schneebaum tries to piece together his original trip to those destinations 30 years ago as a painter/anthropologist/author, during which he became a part of the indigenous communities, lived as their equal and participated in their rituals, simply because he was not satisfied with what life in America had presented him to that point. He was hungry for something more.

In Peru, living as an equal included one act of cannibalism, a rather minor aspect of his journey – and according to him, not pervasive enough to be the film’s focus. But Schneebaum’s cannibalism and homosexuality are misunderstood upon his return as a sort of deviance of appetite when he is confronted by Americans who believe he violated their traditional values. This is revealed in the most entertaining moments of the film in clips of Schneebaum’s talk show appearances in the ’70s and ’80s.

The audience, as expected, is mortified at his cannibalism. Talk show host Charlie Rose, as the conservative country boy, is more offended that Schneebaum participated in the homosexual traditions of Indonesian tribesmen. It’s troublesome because homosexuality and cannibalism are reduced to the same problem – appetite – by the audience of the talk show. The examination of what exactly it means to be hungry and what it means to be content are the thematic preoccupations of the documentary.

Despite its social themes, “River” still is quite cheeky. We follow Schneebaum into a grocery store as the title cards remind us that this is “a modern cannibal tale.” We listen to him joke about what’s for dinner. But we also catch him at those genuine, vulnerable moments when he reveals everything about who he is and what’s in his heart.

As part B-movie, part poem, “River” is an unexpected meditation on life. The film rarely gets preachy. Drawn from Schneebaum’s sentiments, the film’s tone remains one of cautious restraint approaching anxiety. He doesn’t want to go back to revisit his past and openly fights with directors David and Laurie Shapiro. This added footage gives the final product additional integrity because Schneebaum’s hesitation is what holds “River” above the general stream of sensationalist dreck it might have become engulfed in. Schneebaum evades casual classification by living a life that was outside of society’s scope.

There’s no excuse for missing a movie like this. Whatever surface discomfort the subject matter might seem to pose is only superficial. There are no agendas. Schneebaum lived his life unconventionally, but he did so only out of a need to satisfy his personal hunger. Maybe that’s why “River” is such a surprise. Instead of getting a serMonday, the audience finds answers to questions most people would never ask, which may be the highest possible praise for a film. nyou