Christian Bale got fat. Why are we so impressed?

The two-time Sexiest Actor Alive gained some 40 pounds to play Dick Cheney in Vice. Photos of the "incredible" transformation have been rocketing around the internet for months. While a dash of makeup and some prosthetics certainly helped, Bale's physique alone is apparently so convincing that even negative reviews of the film have begrudgingly acknowledged the accomplishment: "Vice is exhausting, but Bale's something to behold," writes The Associated Press. The A.V. Club damns with this faint praise: "Christian Bale's Dick Cheney impression is the only virtue of the glib, superficial Vice."

Yes, Bale makes an unnervingly great Dick Cheney. But why do we still regard this sort of yo-yo dieting as a hallmark of "great" acting?

Bale's extreme body transformation has its roots in the 1980s and 1990s, when Hollywood actors "went to extreme lengths in the pursuit of authenticity, 'becoming' their characters psychologically and physically," film scholar Donna Peberdy writes in her essay on New Hollywood. Robert De Niro, who gained 60 pounds for Raging Bull in 1980, is considered the grandfather of body alternation, followed by Sylvester Stallone in 1997's Cop Land and Edward Norton in 1998's American History X — actors whose collective award nominations helped establish yo-yo dieting as a "legitimate acting technique," a legacy that lasted into the 2000s. "Is an Oscar nomination worth diabetes?" The Washington Post quipped as recently as 2015.

Despite the known health risks to extreme fluctuations in weight, Christian Bale in particular has made a name for himself as "the king of Hollywood yo-yo dieting," from losing more than 60 pounds — down to around 115 — to play a sickly insomniac in 2003's The Machinist to bulking up to 220 to portray Batman in 2005. In 2016, Bale even backed out of a Michael Mann joint after sparking health concerns over the weight he would be required to gain for the part. He had no such reservations preparing to play Cheney; Bale reportedly ate "a lot of pies" and did neck enlarging exercises to obtain the appearance of the vice president.

Why are we all pouring praise on Bale for this? Actresses are not given the same applause for gaining or losing weight for a role. (Actresses' weight gain tends to be limited to muscle when they're bulking up for a role, like Hillary Swank gaining 23 pounds while beefing up for Million Dollar Baby, or extreme weight loss, such as Natalie Portman's for Black Swan.) Indeed, on the rare occasion that an actress "lets herself go" for a role, as Charlize Theron did for her award-winning turn in Monster and again this year in Tully, the media narrative typically focuses on the alleged damage it does to her psyche. "Charlize Theron Reveals She Struggled with Depression After Gaining 50 Pounds for Tully," trumpeted Pure Wow. While Bale's transformation generated Oscar buzz from mere photos of his body, the focus for Theron is on her "very long journey" to now drop the weight. Renée Zellweger, who gained weight for Bridget Jones's Diary in 2001, faced nasty comments in the tabloids for the decision. "No male actor would get such scrutiny if he did the same thing for a role," Zellweger later told The Independent.

It is true that the build of an actor's body has some bearing on inhabiting the mind and movements of the character they play. A person's weight, for example, determines their posture, their gestures, the way they walk and interact with other people. Bale's embodiment of Cheney in Vice isn't limited to him eating enough pies to pack the paunch — it's the way he carries himself like a walking heart attack, the way he slouches in the seats of the Oval Office, and how his heavy breathing cements him as the vice president we all know from the Bush years. Still, even with Bale, makeup and wigs do wonders, and special and practical effects are good enough now that there was no need for Bale to actually force his body through the unhealthy gauntlet of a yo-yo diet to faithfully play his role — think how movie magic made a baby-faced "young" version of Johnny Depp's Jack Sparrow in Pirates of the Caribbean: Dead Men Tell No Tales, or the abundance of digitally enhanced abs in action films. Many stars already get some sort of post-production "beauty work" done, Mashable points out, noting that "hips are narrowed, calves slimmed, turkey-necks tucked." There's no reason this can't also go the other way.

Still, this isn't an endorsement of the fat suit but rather a condemnation of the Hollywood star industry that encourages yo-yo dieting for a role. Full-body transformations are rooted in a systematic failure to cast actors, and especially actresses, who do not meet the unrealistic beauty standards of celebrity. Rather than realistic casting — finding an actor who already carries himself like Dick Cheney, for example — studios instead prefer to give a big-name star a complete makeover so they are "unrecognizable" as themselves. The pressure to gain or lose massive amounts of weight comes, literally, with the part.

An actor is not a better actor for having physically disciplined themselves into gaining weight for a role. While Bale's transformation is impressive, it is more spectacle than talent.