Correlation between anorexia and mass media stereotypes I know anorexia is a complex phenomenon.
I've been reading on Wikipedia that: 


  Sociocultural studies have highlighted the role of cultural factors,
  such as the promotion of thinness as the ideal female form in Western
  industrialized nations, particularly through the media. There is a
  necessary connection between anorexia nervosa and culture; culture may
  be a cause, a trigger, or merely a kind of social address or envelope
  which determines in which segments of society or in which cultures
  anorexia nervosa will appear. The strong thesis of this connection is
  that culture acts as a cause by providing a blueprint for anorexia
  nervosa. A moderate thesis is that a specific cultural factors trigger
  the illness which is determined by many factors including family
  interactions, individual psychology, or biological predisposition.
  Culture change can trigger the emergence of anorexia in adolescent
  girls from immigrant families living in highly industrialized Western
  Societies.[89] People in professions where there is a particular
  social pressure to be thin (such as models and dancers) were much more
  likely to develop anorexia during the course of their career,[90] and
  further research has suggested that those with anorexia have much
  higher contact with cultural sources that promote weight-loss.


Source: Sociological section of Wikipedia on anorexia nervosa

It seems that the mass media can contribute in the diffusion of anorexia.
But I wonder if statistics suggest that this disease has got a boom of cases of in the last years. 

Source: Media effects section of Wikipedia on anorexia nervosa
Short answer
According to a study dating 6 years back, the incidence rate of anorexia nervosa was stable over several decades.

Background
According to a review paper published in 2012, the overall incidence rate of eating disorders, including anorexia, was stable over the previous decades.  However, there was an increase found in the high risk-group of 15–19 year old girls, but that might have been due to earlier detection of anorexia nervosa cases or an earlier age at onset (Smink et al., 2012).

Given that the tendency nowadays is a moving away from the stereotypical barbie-sized waistlines I reckon above study is a valid source of information, as I do not expect the number of anorectic people to be soaring.  

Interestingly, while there are hosts of studies linking mass media and stereotyped ideal bodily proportions, a review study puts these findings in a different spot light. While the authors recognize mass media and eating disorders are linked, they question the size of the impact mass media has on these disorders. They did this by studying the correlation between social media versus negative body image and disordered eating in females (Levine &amp; Murnen, 2009). 

References
- Levine &amp; Murnen, J Soc Clin Psychol (2009); 28: 9-42
- Smink et al., Curr Psychiatry Rep (2012); 14(4): 406–14