Julie & Julia

She turns to Child’s book partly as therapy, partly as anthropology. Cooking used to be about cooking, but in so many ways it’s became about politics, and the politics loosely start to take their toll on Powell’s marriage. Powell’s loving husband, having been trained to accept her as a professional equal, now has to learn to take his wife’s kitchen work seriously. Paul Child is just as fully evolved, but free of any angst over his wife’s success. He’s rooting for her.

Ephron works best when telling tandem stories. The paramours-to-be in “When Harry Met Sally. . .,’’ “Sleepless in Seattle,’’ and “You’ve Got Mail’’ talked and typed their way into idealized romances (gallingly so, in the case of “You’ve Got Mail’’). This time the two halves don’t meet physically or philosophically. Powell’s project becomes a media sensation, but rumor has it that Child finds it frivolous and doesn’t approve (she didn’t). So this might be the first of Ephron’s romantic duplexes to culminate in heartbreak. It also might be the first that manages to comment on itself. The unbearable lightness of some of Ephron’s moviemaking finally meets the sting of her essays. Ephron has been guilty of frivolity, too. But in “Julie & Julia,’’ she doesn’t merely concede that food is life. She celebrates it.

Wesley Morris can be reached at wmorris@globe.com. For more on movies, go to www.boston.com/movienation.