Julia began her petition because she believes today's media gives the wrong impression about body image to teenagers. She is unhappy photos are altered, using Photoshop, to make models appear thinner. Julia has asked Seventeen to publish one spread a month that isn't 'photoshopped'.

Seventeen is one of many magazines criticised for 'photoshopping' models into slim - even skinny - 'hotties'. It creates a body image detached from reality; the 'norm' projected in the media is not the average body that a person should necessarily have. More importantly, often people who don't have trim 'beach bodies' are tagged with negative labels - that they are lazy and worthless.

Today's media certainly plays a big part in shaping our perception about obese people. We talk about how celebrity coverage on television and magazines glorifies skinny figures and demonises the obese.

Yet few people are aware that the same perception is held in fictional dramas and movies. Fat characters are either clownish or unimportant.

This week, we look at how film and television shows influence our perception of obese people.

The Harry Potter movies

Harry was raised by the Dursley family, who are mean, uncaring and cold-hearted. They bully him, treat him badly, and lock him in a tiny room under the stairs.

Yet there is also something to which few people pay much attention - the Dursleys are obese, and eat a lot.

They are demonised because they ill-treat the hero, Harry. Not only are they cruel and insensitive; they are ignorant, too. They know nothing of Harry's magic world. In other words, they are dumb.

Just look at baddie Draco Malfoy's two best friends. They are obese, hot-tempered, and simple-minded - and they are bossed by Malfoy, who is also far from smart.

One of Harry's best friends, the chubby Neville Longbottom, helps defeat Lord Voldemort in the end.

But early on in the films, he is regarded as a quiet, insecure weirdo who always gets into trouble for falling off his broom.

Sadly, his misfortune always becomes a laughing matter for the audience.

Homer Simpson

The Simpsons is a popular American animation series about the Simpson family. Homer, the middle-aged father, has a bulging belly, loves doughnuts and is a 'couch potato': he mostly sits in front of the television eating snacks. Depicted as a loving father, he has many bad habits of fat characters portrayed by the media: he gulps, burps and breaks wind; he is lazy and clumsy, too.

He creates many problems that Marge, his wife, has to solve. The series focuses mainly on his clumsiness and mistakes.

You're the Apple of My Eye

This Taiwanese film - whose Chinese title means, 'In those years, the girl we all went after' - came to Hong Kong last year. Its focus on teenage friendship and 'puppy-love' romance in high school made it a hot topic of discussion in local schools.

Yet at the start of the film, main character Ko Ching-teng is at the centre of a cliche often seen in this kind of school drama: he says there is always a fat boy in every 'typical' group of friends. In this movie, it is Hsieh Ming-ho, played by Steven Hao.

Hsieh is often 'targeted' by his friends because he's the 'fat one'; he loves to eat, and gets upset when Ko makes him drop his food in the opening scene. Hsieh has a crush on the same girl - just like the rest of his friends. But unlike them, he never pursues her. He believes he wouldn't stand a chance because he's overweight.

The influence

Dramas casting obese people in a negative light are dangerous, especially in a school setting. They could influence obese people, suggesting how they should behave among friends - by mostly being quiet and submissive, and lacking confidence to speak their minds. To friends of the obese, such dramas send the wrong signal: that it is OK to give their chubby mates nicknames - or even bully them.

It is important to think about such messages. While enjoying films and dramas, take a step back, and be aware of what is being shown - especially if what you see does not represent reality.

Things to know about obesity

Sometimes, we may think people who are obese or overweight are lazy and lacking self-discipline. This mistaken attitude against fat people is widespread in many developed societies.

From schools to workplaces, research has revealed teachers have shown bias against fat students, and obese employees receive a lower salary compared with their slimmer colleagues.

Such behaviour comes from the idea that if someone is obese, they must lack the ability to take control of their own diet; and, therefore, they'll fail to handle other aspects of their lives. These images are untrue and unfair. Factors leading to obesity can range from one's genes to one's financial situation - other than one's diet.

Also, being a little overweight hasn't always been unwelcome. If you look back in history, many civilisations once regarded plump people as prosperous and blessed.