Mack & Rita

A charming cast led by Diane Keaton can't quite save this dizzy body switcheroo comedy where a young woman only discovers herself when she's turned into a 70-year-old.

“Mack & Rita” is a breezy, dizzy and unambitious entry in the body switcheroo comedy genre. In this case, a frazzled 30-year-old who dreams of being a comfortable old gal suddenly finds herself zapped into a 70-year-old body, where she finally gets to discover her true self.

It’s the sort of thing that would probably be a cable TV movie or streaming fare, but for the presence of the great Diane Keaton. Keaton elevates anything she’s in just by the sheer presence of her vibrant energy, a mix of neurotic anxiety and joie de vivre.

Here she takes a by-the-numbers script and dialogue — by Madeline Walter and Paul Welsh — and punches it up into passable sitcom comedy territory. The idea is that older women have life all figured out, and by spending a month or so in a grandma’s body the youngster can become centered and learn to embrace what she wants in life.

Mack is played by Elizabeth Lail in the bookend sections. A writer who published a well-received first book, she’s now stuck doing social influencer posts and Instagram selfies. It pays the bills and keeps her profile up, but Mack yearns to dive into a novel and generally become a more serious person.

(As is Hollywood tradition, Mack lives in an extravagantly large Los Angeles apartment, just like all financially struggling young people.)

Her best friend, Carla (Taylour Paige — a clearly more engaging actress confined to the wingwoman role), is about to get married, underscoring Mack’s floundering life. Her only quasi-love interest at the moment is Jack, a man/boy neighbor played by Dustin Milligan who dog-watches her pooch, Cheese, when she’s away. (Get it: Mack and Cheese?)

Mack breaks away from the bachelorette activities to visit a New Age tent where she can “Regress and be blessed.” Honestly, Mack just wants to take a minute to chill out. She has fond memories of Grammy Martin, who wore whatever she wanted, did whatever she wanted and made no apologies for any of it.

After an odd encounter with the Zen proprietor (Simon Rex) and his repurposed sensory deprivation machine, she wakes up in her 70-year-old body. There’s enough of a resemblance between Keaton and Lail to cross the suspension bridge of disbelief, and they copy each other’s neurotic mannerisms. Mack is the sort of woman who’s constantly apologizing for just taking up space.

After the expected panic period, she enlists Carla’s aid in a hoax to make everyone believe she is now Mack’s Aunt Rita, and that they’ve swapped apartments for a bit while Mack is working on her novel.

Rita discovers a distinct wardrobe style consisting of a lot of long white pants, jackets, turtleneck sweaters and other couture that would really leave you in a puddle if you tried wearing it in L.A. Subbing in for Mack on her social media events, this “Glam-maw” soon becomes a viral hit in her own right.

She also winds up spending a lot of time with Jack, who finds himself intrigued by this feisty old woman. The become friends and… maybe something more?

A Greek chorus chimes in from time to time, consisting of Carla’s brassy mom (Loretta Devine) and her gal pals (Wendie Mallick, Lois Smith and Amy Hill). They befriend Rita and share a lot of hard-won wisdom, as well as constantly cracking on each other.

A typical piece of banter: “The rest of your life could be the length of one episode of ‘Ellen!’”

Directed by Katie Aselton, “Mack & Rita” has a few things to say about being a famle that should resonate. The essence is that older women are more interesting because they’ve learned to put their fears and hang-ups behind them and stand up for what they want. If only young gals could jump ahead a few steps, they’d be a lot happier.

Unfortunately, the movie constantly falls back on cheap jokes and set-ups. For example, Rita goes to a Pilates class and, despite Carla being experienced at using the contraptions, manages to embarrass herself with a display of accidental physical comedy that would do Buster Keaton proud.

Look, having an older body means you find yourself being less capable of doing some things than you were before. But it doesn’t make you suddenly forget how to work a whatchamajig.

There’s also the obligatory scene of Rita getting stoned, because it’s supposedly funny when mature folks do crazy young things, like boogieing to a ‘60s kaleidoscope of dancing lights. She also tools around in a white 1960s Thunderbird convertible, classic vehicles being another key element in Lazy Screenwriting 101.

You also have to question whether Jack or anybody else really wouldn’t recognize Mack even if she suddenly aged 40 years. Things like voice and expressions don’t really change that much.

Of course, I’m quibbling with the internal logic of a movie where the medium of transformation is a spray-painted old tanning machine. As someone who’s getting up there himself, I should just know when to walk away.