What Causes Bulimia? Understanding the Vicious Cycle

Why does one person develop bulimia while another, who may have experienced similar struggles with food, doesn’t?

Was it dieting? Body image? Stress? Something that happened growing up?

Usually, there isn’t one simple answer.

Bulimia nervosa is a complex eating disorder, and people can develop it for many different reasons. For one person, dieting and body dissatisfaction might play a significant role. For another, difficult emotions, perfectionism, trauma or major life changes may be part of the picture.

Often, several factors overlap. Understanding these factors isn’t about finding someone or something to blame. Instead, it can help make sense of why certain patterns developed. It can also explain why simply telling someone to “just stop” rarely works.

What is Bulimia Nervosa?

Bulimia nervosa involves recurrent episodes of binge eating, followed by behaviours intended to compensate for the binge.

During a binge, someone may eat a large amount of food within a relatively short period. They may also experience a sense of losing control. Afterwards, they might try to “make up for” the binge through behaviours such as vomiting, fasting, excessive exercise or misusing medications.

However, bulimia is about much more than food.

Thoughts about eating, body shape or weight can become closely connected to how someone evaluates themselves. Shame, guilt and secrecy are also common. This means a person can be struggling without the people around them knowing.

We also know eating disorders don’t have a particular ‘look’. People of all body sizes can experience bulimia. Someone’s weight or appearance tells us very little about their relationship with food or the difficulties they may be experiencing.

So, What Causes Bulimia?

There is no single known cause of bulimia.

Instead, eating disorders develop through a combination of biological, psychological and social factors. Some factors may make someone more vulnerable to developing an eating disorder. Others may trigger difficulties or keep the cycle going once it has begun.

Also, having a particular risk factor doesn’t mean someone will develop bulimia. Plenty of people experience body dissatisfaction, difficult life events or perfectionism without developing an eating disorder.

It’s often the combination of factors and how they interact for a particular person that matters.

Dieting and Food Restriction Can Play a Role

For some people, bulimia begins with an attempt to change their eating or body.

They might start skipping meals, cutting out certain foods or following increasingly strict food rules. At first, these changes may even receive praise from other people, particularly in a culture where dieting and weight loss are often treated as inherently positive.

But restriction can have unintended consequences. Not eating enough increases hunger and preoccupation with food. Rigid rules can also make certain foods feel forbidden or emotionally loaded. For some people, this can contribute to episodes of binge eating and an increasingly difficult relationship with food.

Body Image and Social Pressures

We live in a culture that sends strong messages about what bodies are supposedly meant to look like.

These messages can come from social media, advertising, family, peers, sport and fitness environments, or comments about food and bodies that seem harmless at the time.

Experiences of weight stigma have been linked with body dissatisfaction and disordered eating. Importantly, the problem isn’t someone’s body size. It is the judgement, discrimination and pressure they may experience because of it.

When appearance starts to play a bigger role in how someone sees or values themselves, thoughts about food, eating, and body concerns can gradually take up more mental space. Social media can add to these pressures too, although there are practical ways to change your social media feed for better body image.

Even seemingly positive attention about someone’s changing body can reinforce the idea that their appearance is something they need to control.

Sometimes Food Becomes a Way of Coping

Binge eating isn’t always driven by physical hunger alone.

For some people, binge eating can become a way of responding to difficult emotions such as sadness, anxiety, shame or overwhelm. Eating may provide distraction, comfort or temporary relief from feelings that seem difficult to manage in other ways, which can be part of why it can be hard to stop binge eating.

This doesn’t mean someone lacks willpower. As human beings, we naturally look for ways to manage distress, and food can become one of those ways. This may be particularly true when other ways of regulating difficult emotions and self-soothing feel difficult and unavailable.

However, the relief that eating provides may be temporary, and difficult emotions can return afterwards. This can make it harder to find other ways of coping.

Are Some People More Vulnerable to Bulimia?

There are several other factors associated with an increased vulnerability to eating disorders.

These can include perfectionism, low self-esteem, difficulties managing emotions and a tendency towards harsh self-criticism. For some people, long-standing beliefs about themselves can also shape how they respond to difficult situations or perceived failures.

Genetics and family history also appear to play a role, suggesting that some people may have a greater biological vulnerability to developing an eating disorder.

Stressful experiences can matter too. Bulimia may emerge around periods of significant change, relationship difficulties, bullying, trauma, loss or other experiences that leave someone feeling overwhelmed or out of control.

None of these factors should be treated as a simple explanation. Rather, they can form different pieces of a much larger picture.

The Vicious Cycle: Why Bulimia is So Hard to Stop  

Once bulimia develops, the factors that keep it going aren’t necessarily the same factors that caused it in the first place. For example, someone’s initial body dissatisfaction may have led them to start restricting food.

Over time, these behaviours can develop into a vicious cycle of binging and compensatory behaviours, sometimes called ‘the binge-purge cycle‘. Restricting food can increase hunger and make binge eating more likely. Afterwards, feelings of guilt, shame or fear of weight gain may lead someone to compensate through purging, excessive exercise or further restriction.

Although these behaviours might provide temporary relief or a sense of control, they can also reinforce the eating disorder. Someone may return to dieting, setting the cycle in motion again.

Shame can make things harder again.

Someone may promise themselves that each binge will be the last, then feel ashamed when it happens again. That shame can increase secrecy and make reaching out for support feel even more difficult. Understanding this cycle can help shift the question from “Why can’t I just stop?” towards “What is keeping this pattern going?”

This is a more helpful question because it opens the door to understanding what might need to change.

What If I Don’t Feel “Sick Enough”?

One of the difficult things about eating disorders is that they can convince you that your struggles aren’t serious enough to deserve support.

You might compare yourself with other people, tell yourself that you don’t binge or compensate “often enough”, or assume that because your body doesn’t match stereotypes of what an eating disorder looks like, you can’t really be struggling.

But the impact on your wellbeing, relationship with food and everyday life matters, regardless of your body size or whether your experiences seem “better” or “worse” than someone else.

You don’t need to wait for things to become more severe before seeking help. If thoughts and behaviours around food, eating or your body are causing distress or taking up a significant amount of your mental space, that’s worth addressing.

What Does Treatment for Bulimia Involve?

Just as there isn’t one cause of bulimia, support won’t look exactly the same for everyone.

Eating disorder treatment can help you understand both the factors that may have contributed to your difficulties and, importantly, what is keeping the cycle going now. There are several evidence-based psychological treatments for bulimia, including enhanced cognitive behavioural therapy (CBT-E), which helps people understand and change the patterns maintaining their eating disorder.

Working with a psychologist might involve gradually developing a more flexible relationship with food and your body, while also addressing things such as difficult emotions, rigid food rules, perfectionism or self-criticism.

Because eating disorders can affect both physical and psychological health, support may also involve working with other health professionals, such as a GP and dietitian, depending on your individual needs.

And you don’t need to have worked out exactly why this happened before asking for help. Sometimes making sense of how an eating disorder developed is part of the treatment process itself.

Bulimia isn’t Anyone’s Fault

When we’re trying to understand what causes bulimia, it’s important not to turn risk factors into blame.

Parents don’t “cause” eating disorders. Neither does one difficult experience, one diet or one comment about someone’s body. Eating disorders develop through a complicated interaction between someone’s biology, psychology, experiences and environment.

Understanding these contributing factors can help make sense of how bulimia develops. But you don’t need to identify one definitive cause, or have all the answers, before things can improve.

If some of what you’ve read here feels familiar, you deserve to take those concerns seriously. Bulimia can be difficult to overcome, but with the right support, recovery is possible.

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If you’re wondering whether your eating disorder is “serious enough” to deserve support, Sick Enough by Dr Jennifer L. Gaudiani may be a helpful read. The book explores the often-invisible physical impacts of eating disorders and challenges common assumptions about who needs treatment.

You might also like to understand the causes and recovery pathway for anorexia, or how to support someone else with an eating disorder.