A horror film that takes considerable risks and generally makes them work, Jim Mickle’s “We Are What We Are” can be described as a movie about a family of cannibals, but leaving the matter there would be terribly unfair. Eschewing the one-slaughter-after-another mentality that’s practically mandatory in such movies nowadays, it opts for subtlety over grossness and, until the last reel, for creepiness over explicit gore. As such it might disappoint viewers whose major interest is in counting up the corpses and gallons of fake blood, but the more sophisticated will appreciate that it sends shivers up the spine more often than kicking you in the stomach.

The film is adapted from Jorge Michel Grau’s similarly-titled Mexican picture of 2010, but Mickle and his co-writer Nick Damici have altered the narrative substantially. Set in an unspecified small town in Appalachia, it begins with the death of obviously ill Emma Parker (Kassie Depaiva) in a shocking accident outside a convenience store during a driving rainstorm. The focus then turns to the grieving family: her husband Frank (Bill Sage), a religious zealot; daughters Iris (Ambyr Childers) and Rose (Julia Garner), both on the cusp of womanhood; and their little brother Rory (Jack Gore).

It’s gradually revealed that the Parkers have some peculiar culinary needs that aren’t a matter of choice but of physical necessity—the result of events from eighteenth-century family history that are revealed in periodic flashbacks. Their needs are also related to the occasional disappearances that occur in the economically depressed neighborhood.

One person who’s lost a loved one is Doc Barrow (Michael Parks), who also happens to be the town’s medical examiner. As he performs the obligatory autopsy on Emma, he discovers disturbing signs that she was suffering from a most unusual ailment. And when his dog finds a bone washed up by the torrential rainstorm, his suspicions are further aroused and he enlists Deputy Anders (Wyatt Russell) to help him investigate further. The fact that the amiably inept lawman been carrying a torch for Iris since high school makes him eager to help, since the search for more remains will be conducted near the Parker place. Of course, the fact that Frank finds the family in jeopardy just as he’s preparing a special meal doesn’t bode well for anyone.

For the first hour or so, Mickle coasts along mostly on atmosphere, gradually building up the uneasiness until he springs a sudden shock that begins a last act replete with carnage. But even here the level of violence and gore is far more subdued than what occurs in most of today’s horror films. And “We Are What We Are” is also distinctive in that its villains aren’t drawn in a conventional mode. The mindless killer mentality that drives the vast majority of thrillers nowadays is replaced by a strangely sympathetic attitude toward the Parkers, who after all are driven to do what they do not out of mere bloodlust but from genetic compulsion. It’s the trick that Fritz Lang pulled so memorably in “M,” and if Mickle doesn’t match him, that’s hardly a surprise.

He does, however, get unusually shaded performances from his cast, who complement his subtlety of approach with some of their own. Parks and Sage, to be sure, have a tendency to play to the rafters occasionally, but that’s only to be expected—and it does add some dark humor to the mix. The younger players—Childers, Garner, Gore—keep themselves more in check, as does Kelly McGillis as the next-door neighbor whose solicitude might not be entirely appreciated and Russell, who doesn’t overdo the aw-shucks routine as the clueless deputy.

One will never confuse “We Are What We Are” with a big-budget blockbuster, but its low-key look contributes substantially to its impact. Russell Barnes’s production design and Elisabeth Vastola’s costumes give an appropriately odd appearance to the Parker household, and cinematographer Ryan Samul adds a gray, gloomy overlay to the exteriors and a gothic dimness to the interiors. Mickle’s editing maintains his somber directorial pace while ratcheting up the tension at the right points before the explosion of the final reel. The score by Philip Mossman, Darren Morris and Jeff Grace, meanwhile, adds to the mood without calling undue attention to itself.

Hard-core horror fans may find Mickle’s film too sedate for their taste, and in many respects it does represent a throwback to the days when shockers weren’t so in-your-face as they are now. But there are those who will consider its old-fashioned qualities a welcome relief from the nonstop splatter of its rivals.