Print version ISSN 0043-3144
West Indian med. j. vol.59 no.6 Mona Dec. 2010
Efectos de ver páginas web a favor del desorden alimentario: un estudio sistemático
T Sloper Talbot
Charing Cross Hospital, Imperial NHS Trust, United Kingdom
OBJECTIVE: To determine health-related effects of viewing pro-eating disorder (Pro-ED) websites.
METHODS: A systematic review was carried out addressing: 1. The effect of viewing pro-ED websites on 'eating disorder behaviour', 2. The effect of viewing pro-ED websites on viewers' negative and positive affect.
RESULTS: Seven studies were included. Pro-ED viewers compared with controls showed higher levels of dieting and exercise (3 studies, 2 suggesting causation); higher levels of drive for thinness, body dissatisfaction and perfectionism (2 studies, both associative); a reduced likelihood of binging/purging (one study); increased negative affect (two studies); and a positive correlation between viewing pro-ED websites, disease duration and hospitalisations (one study).
CONCLUSION: Viewing pro-ED websites may increase eating disorder behaviour but might not cause it. It may cause increased negative affect after a single short website exposure. For those with eating disorders, viewing is positively correlated with disease duration and hospitalisations. Professionals should be aware ofthese sites and their potential damage for health.
Keywords: Pro anorexia nervosa, pro-eating disorder websites
OBJETIVO: Determinar los efectos para la salud a consecuencia de ver páginas web a favor del desorden alimentario.
MÉTODOS: Se llevó a cabo un estudio sistemático que abordó los siguientes asuntos: 1. El efecto de ver páginas web sobre "comportamientos de desorden alimentario "; 2. El efecto que ver páginas web a favor del desorden alimentario, tiene sobre el afecto negativo y positivo de los usuarios en cuestión.
RESULTADOS: Se incluyeron siete estudios. Los usuarios que ven páginas pro-desorden alimentario mostraron niveles más altos de dieta y ejercicio, en comparación con los controles (3 estudios, 2 que sugieren causalidad); niveles más altos de compulsión a la delgadez, insatisfacción corporal y perfeccionismo (2 estudios, ambos asociativos); una probabilidad reducida de atracones/purga (un estudio); aumento del afecto negativo (dos estudios); y una correlación positiva entre ver páginas web prodesorden alimentario, duración de la enfermedad y hospitalización (un estudio).
CONCLUSIÓN: Ver páginas Web pro-desorden alimentario puede aumentar los comportamientos de desorden alimentario pero podría no ser la causa. Puede producirse un aumento del afecto negativo luego de una sola exposición breve a la página Web. Para aquellas personas con desordenes alimentarios, el ver las páginas Web guarda una correlación positiva con la duración de la enfermedad y las hospitalizaciones. Los profesionales deben tener conciencia de estos sitios y su daño potencial para la salud.
Keywords: Pro anorexia nerviosa, páginas web a favor del desorden alimentario
Pro-eating disorder (pro-ED) websites are a phenomenon of today's growing internet culture. They tend to be pro-anorexia nervosa (pro ana), pro-bulimia nervosa (pro mia) or pro-ED in general. While there are some self identified pro-ED websites that are pro-recovery and do not endorse eating disorders, there are many more websites that do [over 400] (1-3.) This review concentrates on the latter. Note that this review is of the literature concerning the websites and not a review of the websites as such.
Pro-ED websites either directly or indirectly promote eating disorders, by openly saying so, or by virtue of their content. Eating disorders are as defined by the ICD-10 classification. [http://apps.who.int/classifications/apps/icd/icd10online/] (4).
The average prevalence rates in Western Europe and United States of America (USA) for anorexia nervosa and bulimia nervosa among young females are 0.3% and 1%, respectively (5). Those with eating disorders have a mortality risk of about 5.5 times compared with the average of a comparable group of same age and gender (6). Research into pro-ED websites is warranted for these reasons alone.
Pro-ED websites are most commonly composed of:
* Forums where members can post messages on any topic, but usually related to eating disorders.
* 'Thinspiration' galleries - photos of very thin or emaciated women including famous models and actresses, often accompanied by motivational quotes for weight loss.
* 'Tips and tricks' sections - where advice is given on how to maintain an eating disorder [extreme dieting/extreme exercising tips and methods of concealment] (1, 7, 8).
Example postings of these types of websites are:
"its easy to slip, its harder to be disciplined.. i know, as i am a heifer too. But now taking action and sorting my act out..'"
(Quoted from: http://dyingtobethinandperfect.webs.com/anachat.htm Accessed: 09/10/10).
2. 'Thinspiration' Gallery:
3. Tips and Tricks:
"Pick one food for the day, look under the fat burning food section on this site or you can eat something like an apple. Cut it into 4 quarters. Eat one part for breakfast, one for lunch, one for dinner, and you've got one left over for a snack."(www.pro-thinspo.com/Tips.html. Accessed: 05/10/10).
"If you're being watched, try the opaque cup trick; pretend you're eating, and spit the food in the cup while you pretend to be drinking - don't forget to get rid of what's in the cup" (www.freewebs.com/anasgirl/tipstricks.htm. Accessed: 27/05/08).
"Avoid going to the doctor at all costs. If you do have to visit the doctor and you are underweight, here are some things you can try: drink tons of water, if you know you are going to the doctor a few days in advance you can load up on salt; you can lose the water weight a lot easier, Wear heavy clothes and clunky shoes, wear extra jewlry, paint your nails with extra layers (every ounce counts, remember 16 ounces make a pound), if the doctors office isn't too far from your house you can wash your hair right before going, layer the inside bottom of your shoes." (http://whhsbcd.tripod.com/id13.html.Accessed:27/05/08).
The first of the above quotations is an example of 'fat talk' (women talking disparagingly about their bodies and weight). Research has shown that exposure to 'fat talk' can lead to increased body dissatisfaction and eating pathology (9, 10). Exposure to media images of thin women (Fig: 1-3) can lead to increased negative affect (general subjective distress encompassing a range of mood states: eg depression, hostility and anxiety) and body dissatisfaction (11, 12).
Approximately two thirds of adolescents, the age group with the highest prevalence of eating disorders, seek their health information online (13-15). Of these internet users, 50% are looking for ways to lose weight, and 25% are looking for information on eating disorders (16). Such information could be easily sought at any of the vast number of pro-ED websites (3). Indeed, a simple search for "pro anorexia tips" in the search engine 'google' yielded 97 400 hits (August 2010).
Various clinicians, politicians, eating disorder associations/groups, and even viewers ofthese websites have been concerned about these issues because it is believed that viewing pro-ED websites may put the viewer at risk ofvarious negative health effects, such as increased negative affect, body dissatisfaction and eating pathology, which in turn may lead to increases in eating disorders (17-23).
Indeed, in 2008 the French parliament banned such sites, as have web providers such as Yahoo (21).
Alternatively, it has been suggested that the sites provide non-stigmatising support for their users (24-27). An argument of a different kind is about censorship: people have a right to view what they wish provided this does not harm others. Under this argument, this right (within limits) transcends the possibility that they may harm themselves.
The aim of this review is to determine and discuss the various negative and positive health-related effects of viewing pro-ED websites on its viewers.
Criteria for Selecting Studies: All study designs were included. Studies were limited to those written in the English language. The intervention of focus is viewing pro-ED websites.
Primary Outcome: The effect of viewing pro-ED websites on the 'eating disorder behaviour' of viewers. This is an important outcome as eating disorders occur across a spectrum, and certain behaviours, whilst not fitting under the exact diagnostic criteria of an eating disorder, can be pathological in themselves, or can lead on to the development of an eating disorder (28).
For the purpose of this review, eating disorder behaviour is defined as any behaviour which is characteristic of or could lead to developing an eating disorder, such as binging (uncontrollable overeating), purging (self-induced vomiting), excessive dieting (including the use of diet aids) or excessive exercising (29, 30). 'Excessive dieting' is defined using a scale such as the 8-item Adolescent Dieting Scale [ADS] (31) (Appendix 1).
'Excessive exercise' is defined as any one of the following:
(a) exercise which causes severe interference with important activities; or
(b) exercising more than 3 hours per day and distress if unable to exercise; or
(c) frequent exercise at inappropriate times and places and little or no attempt to suppress the behaviour; or
(d) exercising despite more serious injury, illness or medical complication (32).
Some scales, eg the Eating Disorder Inventory (EDI) 'Drive for Thinness' and 'Bulimia' subscales, measure combinations of dietary restraint and physical exercise, bingeing and purging respectively (33).
Secondary Outcome: The effect of viewing pro-ED websites on the negative and positive affect of viewers. Optimum mental health occurs when positive affect is maximized and negative affect is minimized (34). Negative affect has been shown to be an important contributor to the maintenance of eating disorders (35, 36). Markers of negative affect include feeling afraid, scared, nervous, jittery, irritable, hostile, guilty, ashamed, upset or distressed. Positive affect markers include feeling active, alert, attentive, determined, enthusiastic, excited, inspired, interested, proud or strong (37).
Search METHOD: An electronic search was carried out using the NHS Evidence Health Information Resources Healthcare database and the Cochrane database. The full search strategy is outlined in the appendix.
Data Collection and Analysis: The selection of studies follows the Cochrane handbook guidance.
Data extraction: Data were extracted and tabulated by one assessor. No formal synthesis (eg meta-analysis) was undertaken. A narrative summary of the results was deemed more appropriate.
Search RESULTS: The search yielded 141 potentially relevant papers (83 from NHS healthcare database and 58 from the Cochrane library). Of these, 132 were excluded on the basis of their title and abstracts, leaving nine remaining for full text review. A further three were excluded because they did not meet the review's selection criteria. A reference search retrieved one additional relevant paper, leaving seven papers for review.
Primary Outcome: Eating Disorder Behaviour
While one theoretical study hypothesised that viewing pro-anorexia websites would not have an effect on viewers' behaviour (38), all studies that have been carried out suggest otherwise.
Six studies (Bardone-Cone (2007), Wilson, Harper, Csipke, Jett, Custers) included in this review addressed eating disorder behaviour.
Note that all these studies except Wilson (whose population comprised people with eating disorders) were from general populations of teenagers and young adults. Moreover, Wilson in addition to eating disorder behaviour looked at disease duration, hospitalizations and other health outcomes. Importantly, Wilson found that viewing pro-ED websites (and pro-recovery websites) correlated with longer disease duration compared with non-users (p < 0.05) but there was no difference in treatment length. There were also more hospitalizations with pro-ED website users compared with non-users. F (3, 71) = 2.76, p < 0.05. There was no significant difference between pro-ED website users and non-users in other health outcomes, including numbers of missed menses, low bone mineral density and of those with low percentage of ideal body weight.
Bardone-Cone (2007) found that participants who viewed a pro-ED website reported a lower likelihood of overeating or self-induced vomiting compared with those who viewed the control websites (home decor and female fashion).
Harper, Wilson, Csipke all found increased levels of bingeing and purging in pro-ED website users compared with controls.
Harper found that pro-ED website viewers had a higher Bulimia Score (Eating Disorder Inventory subscale) than viewers of the control website. They had a greater tendency towards bingeing which may be followed by the impulse to engage in purging. Similarly, Wilson showed that viewers of pro-ED websites had a greater frequency of learning about and using purging methods than their counterparts in the comparison group (viewers of pro-recovery websites). Csipke found that the majority of pro-ED website viewers answered 'yes' in response to the question: 'Do the websites help you maintain your restricting/fasting/purging etc?' and felt that the pro-ED websites changed their eating behaviour resulting in eating less than they had done prior to viewing the websites.
Although Harper, Wilson and Csipke found higher levels of bingeing and purging in pro-ED users, compared with control groups, the studies are not RCTs, nor was the difference in levels of binging and purging before and after viewing pro-ED websites calculated. Conclusions cannot therefore be drawn about cause and effect.
Excessive Dieting and Excessive Exercising
Neither excessive dieting nor excessive exercising was explicitly addressed by any of the studies. Instead most assessed increased dieting and exercising levels.
Bardone-Cone (2007) found that participants who viewed a pro-ED website reported a greater likelihood of dieting, as well as of exercising in comparison to those who viewed the control websites (home decor and female fashion). Wilson showed that not only did viewers of pro-ED websites have a greater frequency of learning about diet aids and weight loss methods than their counterparts in the comparison group (viewers of pro-recovery websites), but they also had a greater frequency of using these diet aids and weight loss methods. It is important to note here that in this study, pro-recovery websites were found to be similar in content to pro-ED websites, and it is therefore possible that a comparison between pro-ED websites and non-eating disorder websites could show a greater difference in results.
Jett found that participants who viewed the pro-ED website had the greatest reduction in calorie intake post website viewing in comparison to both the exercise site and the non-ED site. On average, they reduced their weekly calorie intake by 2470 calories (p = 0.001). The exercise group reduced their calorie intake by 176 calories on average. Jett also found that 40% of the pro-ED website group and 75% of the exercise/health website group indicated that they would use the exercise/weight control strategies suggested on the websites. At three weeks follow-up, 26% of pro-ED viewers changed eating behaviour to eating more healthily "by eliminating fast foods, 'carbs', 'fatty foods' and 'junk food' and eating more fruits and vegetables".
Increased levels of dieting and/or exercise on their own may not necessarily pose a risk for developing an eating disorder. For an overweight individual, for example, such behaviour could be beneficial. In Bardone-Cone (2007) 17.4% (n = 41) were overweight by BMI classifications. Similarly, in Jett's study, participants had BMI's greater than 18, some of whom may well have been overweight. Also at three weeks' follow-up, there was no evidence of pathological eating disorder behaviour, but rather, evidence of healthier eating after viewing pro-ED websites. Dieting and exercising become risky when they are excessive (29, 30). The evidence pertaining to increased levels of dieting and exercise obtained from the studies reviewed does not give a definite indication of the risk incurred by pro-ED website viewers.
Body Dissatisfaction, Drive for Thinness, and Perfectionism: Both Harper and Custers found that pro-ED website viewers have a greater 'drive for thinness' than viewers of the control website. Harper found that pro-ED website viewers also have greater body dissatisfaction and Custers that they had greater levels of perfectionism. These are all more reliable indicators of eating disorder pathology as they form part of the EDI which is often used as a screening tool for eating disorders (33). However, both studies give only correlational results. It should also be noted that the levels of increase in drive for thinness and body dissatisfaction in Harper s study were approximately the same as for the viewers of professional websites (those giving health information about eating disorders).
In summary, the studies showed that on average, there were higher levels of bingeing and purging in pro-ED website users compared with control groups. However, the only study to assess the effect of viewing pro-ED websites on bingeing and purging (Bardone-Cone et al (2007)), showed that pro-ED website users felt they were less likely to overeat or self-induce vomiting after website viewing than did their counterparts in the control groups. All studies mentioned showed increased levels of dieting and exercising compared with the control groups, but the levels of excessive dieting/excessive exercise were not explicitly measured. The most useful measures for identifying eating disorder pathology were 'drive for thinness', body dissatisfaction and perfectionism, all of which were found to be higher in pro-ED website viewers, though this was only correlational.
Viewing pro-ED websites was shown to be correlated with greater length of illness duration and greater number of hospitalisations.
Secondary Outcome: Negative and Positive Affect
Only the two Bardone-Cone studies addressed this outcome. In both studies, negative and positive affect, before and after viewing eating disorder websites was measured by the PANAS (Positive and Negative Affect Schedule) scales - widely used to measure affect under experimental manipulations (37).
Both studies showed that there were higher levels of increased negative affect in those who had viewed the pro-ED websites than in the control groups. Neither showed a significant change in positive affect.
Pro-eating disorder websites do raise concern. They encourage eating disorder behaviour, advise on extreme dieting/exercising/purging methods, and portray underweight figures as ideal. Many sites state that these eating behaviours are a lifestyle choice rather than a disorder. Thus research into these sites is important.
This is a review of what can be seen as pioneering studies. They alert us to a potentially very important issue and suggest further avenues for research. The research to date has many shortcomings, but it concentrates on what might be done better in future and makes us aware of the limitations under which future research will labour.
These shortcomings include the lack of distinction between increases in dieting and exercising rather than excessive dieting and exercising. Information on the BMI of participants, though measured, was often not related to health risks incurred. Thus it is not clear whether viewing these sites was detrimental or beneficial to some groups, for example the obese. Additionally, we do not know whether viewing of pro-ED websites is a symptom of an underlying eating disorder, or a cause. Nor do we know whether casual and/or intermittent viewing of such websites has a different effect from 'addictive' viewing. Indeed, the causation may be in one direction for casual but in the other for addictive viewing. There is little or nothing in the literature to determine whether passive viewing of a website has a different effect from interactive use of that website.
Above all, the studies show very few consistent results. This is not surprising since they differ so much in populations and methods. More research is needed in order to determine if these websites do harm, and if so, to whom and of what form.
Randomised controlled trials are probably not suitable for this research. An RCT designed to determine whether website viewing were harmful to viewers would have to be impossibly large. At a population rate for anorexia nervosa of 3 in 1000, one would have to enrol 20 000 participants in order to include 30 sufferers of anorexia nervosa in each arm.
Creation of an international registry of data on people with eating disorders would be preferable. Standardised data could include behavioural and attitudinal variables determined by use of validated scales such as the full Eating Disorder Inventory Scale or Eating Attitudes Test. Data might then also include a pro-eating disorder website-viewing behaviour and BMI pre and post viewing. Analysis of associations would shed further light on the effect of website viewing on disease severity. However, it would not answer questions about whether the introduction of website viewing to individuals without eating disorders causes such disorders to emerge.
Perhaps the most important result of this review of research to date will have been to make health professionals more aware of these sites and their possible damage. By having a better knowledge of pro-ED websites, professionals may be able to tailor their therapy to challenge and change the beliefs engendered by these sites.
I would like to thank Dr Alastair Fischer and Professor K Bhui for their overall guidance on producing this review. I would also like to thank Dr Alan Besson for his help with developing an adequate search strategy.
References to Included Studies:
(I) Bardone-Cone A, Cass K. Investigating the effects of pro-anorexia websites. European Eating Disorders Review 2006;14:256-62.
(II) Bardone-Cone A, Cass K. What does viewing a pro-anorexia website do? An experimental examination of website exposure and moderating effects. International Journal of Eating Disorders 2007;40:537-48.
(III) Wilson JL, Peebles R, Hardy KK, Lit IF. Surfing for Thinness: A Pilot Study of Pro-Eating Disorder Web Site Usage in Adolescents with Eating Disorders. Paediatrics 2006;118:1635-43.
(IV) Harper K, Sperry S, Thompson JK. Viewership of Pro-Eating Disorder Websites: Association with Body Image and Eating Disturbances. International Journal of Eating Disorders 2008;41:92-5.
(V) Csipke E, Horne O. Pro-Eating Disorder Web Sites: Users' Opinions. European Eating Disorders Review. 2007;15:196-206.
(VI) S Jett et al. Impact of exposure to pro-eating disorder websites on eating behaviour in college women. European Eating Disorders Review 2010;18:410-16.
(VII) Custers K, Van den Bulck J. Viewership of pro-anorexia websites in seventh, ninth and eleventh graders. European Eating Disorders Review 2009;17:214-9.
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Dr T Sloper Talbot
Charing Cross Hospital, Imperial NHS Trust
Declaration of Interest: None
Declaración de interés: Ninguna.