Obesity & Eating Disorders

Obesity is a term used to describe higher body weight; it is a risk factor for a range of cardio-metabolic illnesses, and is also associated with poor mental health.

People who are described as obese often experience a high degree of stigma and discrimination, which can lead to lower educational attainment and fewer social and employment opportunities.  

Why talk about eating disorders and obesity?

The rates of both eating disorders and obesity are increasing in Australia. Recent evidence shows that the rate of eating disorders among people in larger bodies has increased even more rapidly. One in five people described as obese has disordered eating patterns.

The link between body size and eating disorders

Body size and eating disorders are interrelated. Larger body size is both a risk factor for developing an eating disorder and a common outcome for individuals with bulimia nervosa (BN) and binge eating disorder (BED). People with BED have an increased likelihood of weight gain and related complications, and experience a higher rate of medical and psychological problems than people in larger bodies who do not have BED.

Media and public health messages

Eating disorders are characterised by extreme concerns about body weight and shape, and unhealthy relationships with food. This can apply to people at any size, and people in larger bodies may be at greater risk because of the messages that society sends them about their body needing to be changed or ‘fixed.’ A person may respond to this by:

  • Restricting food intake and initiating a starvation response in their body, which can occur at any size following rapid weight loss;
  • Feeling a loss of control around food and consuming a lot of it in a short space of time (a binge), which may or may not be followed by attempts to rid the body of the food consumed (a purge).


The importance of collaboration

In light of the considerable overlap between conditions, there is an urgent need for greater collaboration between the obesity treatment and eating disorders sectors, from clinical practice through to public health policy.

Weight loss services and eating disorders awareness

People with eating disorders are more than twice as likely to contact health professionals or weight loss centres for weight reduction assistance than they are to seek treatment specifically for their disorder. Their active participation in weight loss may contribute to the development of disordered eating or eating disorders. It is critical that weight loss services incorporate an awareness of this health risk into all programming.

From healthy dietary patterns to eating disorders

Obesity interventions targeting youth could contribute to the development of eating disorders in later years. Similar concerns have been raised about obesity treatment initiatives which may contribute to the onset of disordered eating behaviours in people of any age, by increasing anxiety about body shape and weight and the development of unhealthy weight loss behaviours.

It is imperative that clinicians are aware of the large and consistent body of evidence reporting harms from unhealthy dieting behaviours, and monitor patients to ensure that healthy dietary patterns do not transition into unhealthy diets over time. 

Positive public health campaigns

Obesity-prevention campaigns may increase eating disorder risk factors such as preoccupation with body weight or shape, or restrictive eating. Public health campaigns that emphasise an ideal weight and shape are associated with increased stigma and body dissatisfaction in individuals of all weights. Developing approaches to public health which support healthy relationships with food and bodies and which do no harm to others must be a priority for the obesity treatment and eating disorders sectors together.


Treatments and outcomes

Health professionals working with eating disorders or weight loss for people in larger bodies should be informed about the physical and psychological features of both eating disorders and being of size, as well as the significant shared space between them.

Many treatments are used to help people lose weight. Lifestyle interventions such as diet, exercise and behavioural or psychological approaches are the most commonly used first-line approach, with medication or bariatric surgery in more complex cases.

Positive Treatments

Obesity interventions as a whole can be effective at reducing weight, which may be associated with improvements in health and quality of life. Improvements in eating disorder psychopathology have been seen in weight loss interventions that incorporate behavioural and psychological components.

However, relatively few studies have assessed the impact of weight loss interventions on eating disorders outcomes. It is therefore difficult to know whether improvements were a result of the supportive treatment context or whether they were related to weight loss.


In contrast, cognitive and behavioural improvements are not sustained following bariatric surgery and medications have not been shown to be consistently effective. Surgery and registered medication consistently reduce weight, but are also associated with adverse effects that ranged from mild to severe, including suicide.

In addition, some signs and symptoms of eating disorders may initially be seen as treatment benefits. For example, increased physical activity and control and discipline over hunger and eating may be viewed as positive outcomes from weight reduction interventions, but are also a sign of increasing disease severity for individuals with eating disorders.


Interventions and Public Health 

Prevention initiatives targeting obesity may increase eating disorder risk factors. In contrast, prevention strategies that integrate media literacy, body satisfaction and self-esteem with messages on general healthy eating and physical activity for enjoyment may improve outcomes while reducing weight stigma and other unintended harm. 

Integrated approach

Integrated campaigns aimed at preventing the spectrum of eating- and weight-related problems are time- and cost-effective, improve coherence in messaging, reduce harms from conflicting messaging, and create avenues for collaboration and coordination across the health sector.

Guidelines for public health messages

  • Messages should focus on health, not weight, and have a holistic perspective which includes social, emotional and physical aspects of health
  • Weight is not a behaviour and therefore not an appropriate target for behaviour modification
  • People of all sizes deserve a nurturing environment and will benefit from a healthy lifestyle and positive self-image
  • The ideal intervention is integrated, addresses risk factors for the spectrum of weight-related problems, and promotes protective behaviours
  • Interventions should honour the role of parents and carers, where relevant, and support them to model healthy behaviours at home without overemphasising weight
  • Community members should be included in the planning process to ensure that interventions are sensitive to diverse norms, cultural traditions and practices
  • It is important that interventions are evaluated by qualified health care providers and/or researchers, who are familiar with the research on risk factors for eating disorders.


Recommendations and next steps

Existing and new treatments should be evidence-based and should include long-term follow up which includes routine assessments of psychological well-being alongside physical health.

There is a need for improved clinical tools and practices, greater dialogue and collaboration between sectors, and increased research into the areas of overlap between larger bodies and eating disorders. In particular, the following areas need attention.

Areas of attention

  • A collaborative approach that addresses weight stigma and promotes healthy eating practices without encouraging dieting or weight preoccupation
  • Better training of health professionals to increase awareness about the physical and psychological features and shared, modifiable risk factors
  • Evidence based treatment strategies incorporating behavioural and psychological interventions on eating disorders outcomes and weight in a holistic program of care.
  • Longer-term monitoring and maintenance sessions with a combined emphasis on stabilising weight, well-being, and healthy activity and eating patterns
  • Improved postsurgical follow-up care. Bariatric surgery patients present unique challenges that must be carefully monitored, such as the development of disordered eating behaviours with and without concomitant eating disorders psychopathology


NEDC Report

The NEDC has published a systematic review of all studies which reported on obesity treatments, including dietary, exercise, behavioural, psychological, pharmacological and surgical interventions for weight loss. 134 studies were included in the review.

Some of the key findings are shown on this page. The full review, including discussion of all treatment modes and their impact on eating disorder outcomes, study limitations and recommendations for practice and research can be accessed here


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