There are 4 main characteristics that are caused by anorexia nervosa, and they are all serious health issues. Sufferers of AN will get anxiety and have an excessive fear of being fat and putting on weight. However, the opposite happens as they lose weight as a consequence of starving themselves. If their weight drops below 85% of their average weight then they will be diagnosed with AN. They have body image distortion and see themselves as fat, rather than their real image, which is bad for their self esteem and extends their disorder. Amenorrhoea occurs and after 3 months, it is a clinical characteristic of anorexia, because the lack of nutrition means your body wouldn't be prepared to provide for a baby to it stops the menstrual cycle.

The media is full of thin models and air brushed photographs which portrays thin as the 'perfect' body image. Adolescents with low self-esteem- particularly females- are largely influenced by this and compare themselves to the images of models and celebrities (Jones and Buckingham 2005). This can lead to girls losing weight to reach the 'perfect' image that their idols have. This is supported by Becker (2002) who studied teenage girls from Fiji and found that after the introduction of T.V. in 1995, the girls stated that they wanted to have the figures of the actresses and lose weight. Not only does it show media effects, but it shows it is applicable to other cultures who are usually less exposed to media. However it has been found that giving people awareness and instructional intervention before they are exposed to media, will prevent the effects of media such as anorexia (Yamamiya et al 2005).This means that media is a cause of anorexia, but it can be prevented. Since the realisation that media effects peoples eating behavior in a negative fashion, changes have been made. The fashion industry in France has started promoting a diversity of body sizes in their models, and have signed a charter of goodwill. This shows that the effects of anorexia are being noticed and action is being taken to reverse it.

Other cultures do not place as much value on the thinness of women. Large body sizes are considered to show fertility, nurturance and attractiveness in non-westernised cultures (Pollack 1995). It is thought that anorexia nervosa is much less common in black populations than in white westernised populations. Grabe and Hyde (2006) carried out a meta-analysis on 98 studies and found African-American women reported less body-dissatisfaction than Caucasian and Hispanic women, supporting that there is a difference in ethnicity and eating behavior. However in contrast to this, Cachelin and Regan (2006) found no differences in eating behavior between African-American and Caucasian women. This shows that the correlation between ethnicity and eating behavior isn't as straight forward as some studies suggest, and that more factors will be involved.

Bruch (1973) claimed that anorexia depends on our upbringing in childhood. Children with 'effective' parents would get fed when hungry and comforted when anxious, but children with 'ineffective' parents would get the opposite. When the child crys, the parents would feed them when anxious and comfort them when hungry, because they do not know the difference between the child's crys. This would lead to the child being confused about their internal state and they would rely heavily on their parents. When they reach adolescents, they want a sense of autonomy, so they take control of their eating habits, and starve themselves to be in control of their own body. Steiner et al (1991) supports this theory, as he observed parents of children with AN, and the parents had a tendency to define their children's needs rather than letting them define themselves alone, and this fits with Bruch's theory. In further support of this, Button and Warren (2001) found AN sufferers heavily rely on other opinions and they feel a lack of control over their own body. These would be fitting consequences to being a child with an 'ineffective' parent, so it is supporting Bruch. On the other hand, this theory is highly reductionist as it doesn't take social influences and other approaches into account, so it is bias to childhood experiences.

Personality traits of a certain kind are thought to be associated with AN and perfectionism is one example. Strober et al (2006) showed that there is a high link between the two- 73% of girls and 50 % of boys suffering AN also were perfectionists. Nilsson et al (1999) showed further support when he found high perfectionism levels were more common in longer AN illnesses, and lower levels of perfectionism were linked with shorter AN illnesses. This proves that the two factors have a correlation. Halmi et al (2000) did a larger study, looking at 322 women across Europe and the US with a history of anorexia. It highlighted that AN sufferers got a lot higher scores on the multidimensional perfectionism scale, than healthy women. He also found the same as Nilsson, that the severity of the perfectionism correlates with the severity of the AN. In further addition, the study implied that anorexia has genetic connections, as perfectionism is a character that runs in the family. There are issues with the methodology in the studies that look at the personality traits. It is difficult to distinguish between short-term traits that have come about by starvation, to long term traits that were there without the AN. This issue makes it difficult to see if one is a cause of the other, and makes the studies slightly less reliable.

Another approach that could be taken is the behavioral approach, which looks at conditioning andsocial learning theory. This approach suggests that we condition 'thin' appearances to be the 'perfect' figure. Anorexia sufferers associate 'thinness' with success and attractiveness, so they starve themselves to reach that goal (Harrison 2001). The social learning theory suggests that we are reinforced by others approval of weight loss in the earlier stages of AN, so we carry on losing more weight