Is the constant diet of handsome men and beautiful women that we are fed by the media making us feel insecure about our own appearance and damaging our self-esteem? Louise Holden wonders if we are victimised, or just paranoid

We absorb so many hours of media each day it's easy to take the images we see there for granted, and not to question the discrepancy between what we see and what is real.

For example, thinness is a media standard for female beauty. In fact, today's fashion models weigh 23 per cent less than the average female. A young woman between the ages of 18 and 34 has a 7 per cent chance of being as slim as a catwalk model and a 1 per cent chance of being as thin as a supermodel.

"The media markets desire. And by reproducing ideals that are absurdly out of line with what real bodies really do look like... the media perpetuates a market for frustration and disappointment. Its customers will never disappear," writes Paul Hamburg, an assistant professor of psychiatry at Harvard Medical School in the US.

Considering that the diet industry alone generates €33 billion, it seems that making people feel bad about themselves is a good way of making money.

Distorted body image is known to affect many women and girls, whether the media is to blame or not. But there is growing pressure on men and boys to match up to the images of the stars. Doctors, in the US especially, have seen an increase in obsessive weight training and the use of anabolic steroids and dietary supplements that promise bigger muscles.

Male height is taken for granted in the media and where a leading man is shorter than a leading lady (which is often the case), scenes are doctored to ensure that this is not obvious to the audience.

The majority of teenagers with eating disorders such as anorexia are female (90 per cent), but experts believe the number of males affected is growing. Many cases may not be reported, since males are reluctant to acknowledge any illness associated with females.

Critics argue that perfect images in the media can do more subtle damage to human beings than triggering eating disorders. Male and female stereotypes portray the perfect face, the perfect body and the ideal build. When we see enough "ideal" people we start to look at ourselves unfavourably. We begin to lose self-esteem when we want to be like someone else. We expect others to fit the stereotypes too - we like the stereotypes more than the real people. This can cause problems in relationships, making it difficult for us to see past the surface.

Just as fashions in clothing change, body fashions change too. The difference is that a change of clothes is simple to achieve. A change of body is not. Nonetheless, the number of people undergoing major surgery to change their bodies is always on the up. J Lo's bottom has inspired a new trend in below-the-waist surgical implants. Kate Moss was credited with bringing in the flat chest.

Because an image provides such an instant message, it is tempting for the media to use physical characteristics to suggest personality types. For example, when a "bully" is portrayed on TV, he or she is almost always overweight. In reality, we know that bullies come in all shapes and sizes. If an intelligent or nerdy character is featured, he or she often wears glasses. The hero of a film is almost always white. The heroine is often blonde. Blondes are also sometimes portrayed as less intelligent . Naturally we know that none of these "visual clues" reflect reality.

Or do we? Visual short cuts like these save programme and film makers the trouble of revealing a character's personality through dialogue or action. But do we, as the audience, use the same short cuts in everyday life? Do we make snap decisions about people based on their appearance, to save ourselves the trouble of finding out the truth?

Television shows like Pop Idol and Pop Stars make the message clear. The judges in these programmes never tire of telling us how important it is for a pop star to have "the right look". Candidates have been rejected for having piercings, hair lips, large bodies and a range of other characteristics that have nothing to do with talent or performance.

But is it a bit paranoid to blame TV shows,

ads, films and the music industry for our own insecurities? Shouldn't we have the personal strength and common sense to distinguish between the fantasy and real life? And if the media projects false images, whose fault is it? What is media if not a mirror of our own tastes and values?