Infinite Life is about five American women, all dumpling-shaped, who sit in a hotel garden observing a hunger strike. Some of them haven’t touched food for days, some for weeks. ‘Don’t be afraid to puke,’ counsels one of the dumplings. ‘Puking is good.’ They pass their afternoons wittering inanely about nothing at all. One dumpling is an air hostess, another works in banking, a third has a job as a fast-food executive. Or so they claim. Each of the dumplings might be lying to the others but it would make no difference because nothing connects them, and they have no stake in the situation other than the desire to burn up time.

It doesn’t feel like a play but a prank staged by psychologists

After a while it transpires that the dumplings are not hunger-strikers but weight-watchers hoping to cure their many ailments by fasting. The main dumpling, Sofi, is troubled by an infected clitoris which makes her groin feel ‘like a blow-torch’. Whenever the chance arises, she treats her itchy genitals with a seven-hour sex marathon. Another dumpling tells a story about driving through a eucalyptus grove. That’s the end of the story, by the way. A third dumpling recites passages from the trash novel she’s reading. A fourth jabbers about Christian Science.

Sofi, who appears to be the best-educated dumpling, holds forthright views about sex and she announces that online porn is dominated by ‘enormous idiot rapists’. One night she leaves a hysterical message on her lover’s phone in which she describes being sodomised by a toasted Hispanic delicacy. Then she lies on her back masturbating.

After a few days a new dumpling – male, half-naked and white-haired – joins the fat farm. The other dumplings discuss the possibility that he’s a mirage generated by their calorie-starved and hallucinating minds. Sofi starts to flirt with the imaginary male and they form a bond over some photographs of a diseased colon. That’s the highlight of the show. Did their amorous conversation actually happen or was it a figment of Sofi’s fevered brain? Hard to say.

After two hours of stage-time, the dumplings pack up their belongings and leave, one by one. End of diet. End of show. None of the dumplings has shed any weight and none has acquired a suntan despite roasting for weeks in the California sunshine. Infinite Life doesn’t feel like a play but a prank staged by psychologists who want to see how much vacuous poppycock a paying audience will bear before they demand a refund. It’s rare to find a show that would be improved if the characters were to starve to death – but here it is.

The design is as drab and cursory as the script: the dumplings lie on grey loungers surrounded by concrete walls painted magnolia. Their dreary, shapeless costumes look like rejects from a jumble sale, but it’s possible that the actors were told to slob into the theatre wearing whatever tat they crashed out in the previous night. As for the dialogue, it might have been improvised on the spot.

This lazy, brain-dead anti-drama originated in America where theatre-makers seem to hold their audiences in utter contempt. The National should set an example and not sink to the worst artistic standards in the world.

The panto at Stratford Jack and the Beanstalk starts as a Brechtian allegory about the toiling masses of ‘Splatford’ who extract bilge from nearby mudflats which is then sold by capitalists as a beauty product. After this brief Marxist introduction, the panto proper begins. The setting is a shop run by Milky Linda, a cross-dressing dairy magnate, who fears that her business is about to fold. Milky Linda is terrorised by two gormless thugs, one called Flesh Creep who wears leather clothes, and the other called Bill, whose looks are marred by a missing tooth and a cheap ginger wig. Milky Linda puts her faith in her drippy son, Jack, and his best friend, Winnie the Moo, who provides milk for the shop. Given that the show is aimed at kids, the narrative set-up is very elaborate – and we haven’t even reached the magic beans, the horrible ogre and the golden eggs. Maybe kids don’t much care.

My companion, River, aged eight, seemed to enjoy this scruffy, slapdash show with its queasy colour scheme of yellows, greens, blues and purples. The designer, Lily Arnold, covers too many of the props and costumes with lettering. It’s a panto you read rather than watch. ‘Look at the foxes,’ I said to River as three actors appeared dressed as furry urban scavengers. ‘That’s a hedgehog, a badger and a wolf,’ he corrected me. The outstanding performer is Savanna Jeffrey (Winnie the Moo), who acts very well and sings beautifully. I asked River for his final verdict. ‘Brilliant, average, or rubbish?’ I suggested. ‘In the middle,’ he said. ‘I quite liked it but I might see better.’