Sarah Sands: Do we really want friends and family to be our ballet critics?

It was not chivalrous of Alastair Macaulay, the British dance critic of The New York Times, to write that Jenifer Ringer, principal dancer of the New York City Ballet, looked overweight in The Nutcracker. To say that a woman with a history of bulimia and anorexia looked as if she had had "one plum too many" as the Sugar Plum Fairy showed an undeniable emotional insensitivity. The incident coincides with the imminent release of Black Swan, a film about the grotesque physical demands made on dancers, and with a wave of ballet mania. So Macaulay's remark has hit black ice in front of a mass audience. As Natalie Portman, star of Black Swan, asked rhetorically: "In whatever other fields is it acceptable to judge artists by how big they are?"

Of course, Macaulay is absolutely in the right. If critics must judge according to the self-esteem of the performers rather than the merits of the production, then there is no point in publishing. Friends and family can write the reviews. Portman is wrong. Ballet is the one art form where it is absolutely relevant to discuss the physical make-up. If it does not matter what a dancer looks like, why not just listen to ballet on the radio instead?

Jenifer Ringer issued a dignified response, acknowledging that "my body is part of my art form" and that "I do have, I guess, a more womanly type than the stereotypical ballerina".

Are dancers, like models, victims of a distorted view of physical beauty? I don't think so. Last summer, I watched the Bolshoi ballet rehearse in Moscow and their shapes were mostly what distinguished the stars from the chorus. There was no room for hurt feelings in that room. Entire careers were scotched by a dismissive nod of the head: legs too short, lines imperfect, not swift enough, tall enough, beautiful enough. Top dancers are like racehorses: no one suggests allowing a cart horse to race at Ascot to make it feel better. Excellence is exhilarating but it is not kind.

Sometimes a dancer can, excitingly, break through despite imperfection. I watched the male wonder of the Bolshoi, Ivan Vasiliev, dance opposite the female star Natalia Osipova at the Royal Opera House. She was physically breathtaking, he so despite his physical sturdiness and low centre of gravity. The other dancers could not match the couple's dazzling charisma but could at least be thin.

Ringer consoled herself by saying that Macaulay's was "just one person's opinion". That may be true, but unfortunately it is the person whose opinion weighs most. However frustrated and furious performers are to be judged by someone who could not do their job, that is the deal. Some people dish it out; others have to take it.

The judgements may seem subjective to the point of absurd. For instance, the production of A Flea in Her Ear that opened at the Old Vic last week was ardently praised by some critics and damned by others. But integrity and intensity of response is the critic's gift. And it is the critics who bring in the audiences as well as putting them off. Look at how evangelical they have been about the RSC's musical Matilda.

On Thursday, I went to see Matthew Bourne's radical Cinderella at Sadler's Wells. It was packed – Matthew Bourne is a feted figure in dance, partly thanks to to the encouragement of the critic Alastair Macaulay. It works both ways. So you cannot have your cake and eat it. Especially if you are playing the Sugar Plum Fairy.

Sarah Sands is deputy editor of the 'London Evening Standard'