Bariatric Surgery, Disordered Eating & Eating Disorders

Disordered Eating & Bariatric Surgery

Weight loss surgery, also known as bariatric surgery, is an increasingly popular treatment for people suffering from morbid obesity. A lot of people seeking bariatric surgery may already struggle with disordered eating behaviours, or an eating disorder, that often has contributed to their weight issues.

A pre-existing eating disorder could interfere with the surgery outcomes and the desired weight loss. Moreover, some people may develop eating disorders or problematic eating behaviours following their surgery.

The WeightMatters Team offers psychological and nutritional screening for any eating related issues before your surgery to ensure you are prepared for the lifestyle changes to follow. You will also receive ongoing psychological and nutritional support after your surgery to ensure you adapt well to the changes in your eating, habits and body image.

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If you are seeking bariatric surgery, it is likely that you participate, or have participated in, repeated strict dieting regimes which can often lead to disordered eating behaviours, which further contribute to your struggle with weight.

Some common disordered eating behaviours seen pre-surgery include:

  • Overeating
  • Binge eating
  • Compulsive eating
  • Grazing (picking and nibbling)
  • Emotional eating
  • Stress eating
  • Night eating
  • Skipping meals

Evidence also suggests that some people seeking weight loss surgery may also meet the criteria for an eating disorder diagnosis. In these cases, it is recommended that you receive treatment for your eating disorder before undergoing surgery.

Binge eating disorder, consuming large quantities of food in a brief period of time, is the most common disorder seen in people seeking bariatric surgery. Other common eating issues include night eating syndrome, bulimia nervosa, and atypical anorexia which is often underdiagnosed in overweight individuals.

The presence of an eating disorder pre-surgery is likely to interfere with the surgery outcome leading to less weight loss, or more weight gain, and in some cases worsen the eating disorder symptoms if left untreated.

Our experienced therapy team will evaluate your eating behaviour and help you manage any disordered eating behaviours pre-op. We will show you how to best manage your emotions and stress without using food to soothe yourself.


Adaptive responses (left) to maladaptive responses (right)


People who have had weight loss surgery experience physiological and anatomical changes that can change their ability to eat and digest food as normal. They may experience symptoms that mimic eating disorder behaviours, or participate in compensatory behaviours to manage uncomfortable feelings from having consumed more food than their body can tolerate, or foods that may be hard to digest.

Some common disordered eating behaviours seen post-surgery include:


This may happen after consuming large amounts of foods in order to relieve uncomfortable feelings of being too full after eating, or being unable to digest certain foods.

Left unmanaged, some people may use self-induced vomiting as a way to control their weight and compensate for their eating, which could lead to the development of bulimia or atypical anorexia nervosa.


Grazing is a behaviour where you are picking, nibbling and snack eating. This can start as a mindless habit, but over time can develop into a compulsive behaviour with a loss of control over eating. Evidence suggests that grazing might be used as an alternative to binge eating post -surgery. Due to not being able to eat large amounts of food in one go, some people may instead keep eating smaller portions of foods throughout the day without necessarily feeling hungry.


Dumping refers to the rapid gastric emptying of food, especially sugars, into your small intestine, which can lead to a variety of unpleasant symptoms:

  • Abdominal cramps and pain
  • Sweating
  • Nausea
  • Diarrhea
  • Drop in energy levels

Some people may intentionally eat foods that cause such symptoms as a way to control their weight and compensate for what they have eaten.


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Some people may also show symptoms that meet the criteria of eating disorders including:

Loss of Control When Eating

This is a common reported symptom of binge eating disorder (BED). However, due to the anatomical changes and people being unable to consume large amounts of food in one go, people do not meet the full criteria for BED, and it has been referred to as Bariatric Binge Eating Disorder.

Bulimia or Atypical Anorexia

When eating is accompanied by compensatory behaviours such as vomiting, restriction of food, or excessive exercise.

Night Eating Syndrome

Consuming large amounts of food late at night, or waking up in the middle of the night to eat.

Chew and Spitting Disorder

Chewing and spitting out food as a way to control weight. This is often used as an alternative to binge eating from individuals post -surgery.

Post Surgical Eating Avoidance Disorder (PSEAD)

This is a phobic avoidance of eating as a result of a fear of choking or vomiting. Some people might start experiencing a choking sensation and stop eating.


Many studies show that there is a correlation between disordered eating behaviours and poor surgery outcomes, with poor weight loss or even weight regain following surgery.

The more disordered the eating behaviour is before surgery, if not dealt with in the pre -op stage, it can lead to the development of more serious eating disorders.

We believe that psychological and nutritional support pre-op, and post-op, results in the best outcomes from your weight loss surgery experience.

WeightMatters has over 14 years experience specialising in the treatment of eating behaviour, and we have worked with many clients pre and post surgery.

We look forward to supporting you in your weight loss surgery journey with us.