The Emotional and Physical Health Effects of Eating Disorders on the Body and Mind
Eating disorders are often thought of primarily as psychological conditions. While thoughts, emotions and behaviours around food and the body are central to an eating disorder, their impact is rarely confined to mental health.
Eating disorders can affect almost every system in the body. They can influence the heart and circulation, digestion, hormones, bones, teeth, sleep, concentration and energy levels. At the same time, living with an eating disorder can be emotionally exhausting, increasing anxiety, low mood, isolation and preoccupation with food or body image.
These effects can occur in anorexia nervosa, bulimia nervosa, binge eating disorder (BED), OSFED and other eating disorders. Importantly, you cannot necessarily tell how physically or psychologically unwell somebody is by looking at them. Eating disorders affect people of all ages, genders and body sizes, and significant medical complications can occur without somebody appearing underweight.
The reassuring part is that many of the health effects of eating disorders can improve considerably with recovery. Getting the right treatment early, and paying attention to both physical and psychological health, can make an important difference.
Physical and Emotional Effects of Eating Disorders
| Physical health effects | Emotional and psychological effects |
| Changes in heart rate, blood pressure and circulation | Anxiety, low mood and emotional distress |
| Digestive discomfort, bloating and constipation | Guilt, shame and fears around eating |
| Hormonal changes and reduced bone density | Obsessive thoughts about food, weight and body image |
| Dental erosion and other oral health problems | Social withdrawal and strained relationships |
| Fatigue, poor sleep and difficulty concentrating | Reduced self-esteem and difficulties managing emotions |
Eating disorders can affect both physical and mental health, with symptoms varying depending on the individual, their eating disorder behaviours and their medical history.
How can an eating disorder affect physical health?
The physical effects of an eating disorder vary considerably from person to person. They depend partly on the eating disorder itself and on behaviours such as restriction, binge eating, vomiting, laxative or diuretic misuse and excessive or compulsive exercise.
They can also be influenced by how long somebody has been unwell, the speed of any weight loss or nutritional change, hydration and electrolyte balance, and their individual medical history.
This is why specialist assessment is important. The NICE guidelines for eating disorders recommend assessing both physical health and associated mental health difficulties, rather than relying on weight or appearance alone. This helps us understand what has actually been happening to someone’s body.
Heart and circulation
Restriction, malnutrition, dehydration and electrolyte disturbances can all affect cardiovascular health. Some people develop a low heart rate or blood pressure, dizziness, fainting or difficulty regulating their body temperature.
Electrolyte disturbances, particularly those associated with vomiting, laxative misuse or severe restriction, can affect the rhythm of the heart and may become medically dangerous.
People with eating disorders therefore sometimes need blood tests, an ECG and monitoring of their pulse and blood pressure alongside psychological treatment. Where there are concerns about medical stability, outpatient treatment alone may not be appropriate until someone has been medically assessed.
Digestion and gastrointestinal symptoms
Digestive problems are extremely common in eating disorders.
People may experience bloating, abdominal discomfort, constipation, reflux, nausea or feeling unusually full after relatively small amounts of food. Binge eating and purging can also cause gastrointestinal symptoms, while repeated vomiting can irritate or damage the oesophagus.
These symptoms can unfortunately reinforce the eating disorder. Someone who feels very bloated after eating, for example, may understandably interpret this as evidence that eating more is making things worse.
Often, however, digestive symptoms are themselves partly a consequence of disrupted or inadequate nutrition. As eating becomes more regular and the body recovers, gastrointestinal functioning will frequently improve, although this can take time.
Hormones, fertility and bone health
Inadequate energy availability can affect the body’s hormonal systems. Menstrual periods may become irregular or stop, but hormonal effects are not limited to people who menstruate. Eating disorders can affect sex hormones, libido, fertility, thyroid function and other endocrine processes in people of any gender.
Over time, changes in hormones and inadequate nutrition can also affect bone health, particularly during adolescence and early adulthood when bones are still developing. Reduced bone density can increase the risk of osteopenia, osteoporosis and fractures.
This is one reason why early treatment is particularly important for children and adolescents, although bone health is relevant in adults too.
Teeth and oral health
Repeated vomiting can expose the teeth to stomach acid, gradually eroding tooth enamel and increasing sensitivity and dental problems. Some people also experience a sore throat, swollen salivary glands or irritation around the mouth.
Nutritional deficiencies and dehydration can affect oral health more generally. Dental care can therefore be an important, but sometimes overlooked, part of recovery.
Energy, concentration and everyday functioning
The effects of an eating disorder are not always dramatic medical events. Sometimes they appear as a gradual loss of wellbeing.
Someone may feel constantly cold or tired, struggle to concentrate, sleep poorly or find that work, school, university, parenting or socialising requires much more effort than it used to.
When the brain and body are not receiving consistent nutrition, cognitive and emotional functioning can also be affected. Thinking may become more rigid, decision-making harder and thoughts about food increasingly dominant.
The emotional and psychological effects of eating disorders
Physical and psychological effects do not happen independently of one another.
Eating disorders can bring intense anxiety around food, weight, shape or eating with other people. There may be guilt or shame after eating, bingeing or purging, or a persistent feeling of having failed when self-imposed food or exercise rules are not followed.
Over time, life can become increasingly organised around the eating disorder.
Someone may avoid restaurants, holidays or social occasions because food feels too difficult. They may withdraw from friends or partners, find family relationships increasingly strained, or lose interest in activities that previously mattered to them.
Low mood, anxiety, obsessive or compulsive features, perfectionism and difficulties with self-esteem commonly occur alongside eating disorders. Some people also experience self-harm or suicidal thoughts, which require careful assessment and appropriate mental health support.
It is also important not to assume that every psychological difficulty is simply caused by the eating disorder. ADHD, autism, OCD, trauma, depression and anxiety disorders can coexist with eating disorders and may need to be understood as part of the overall clinical picture.
Can the health effects of an eating disorder be reversed?
Many can.
Heart rate and blood pressure can normalise, energy and concentration can return, hormonal functioning may recover and gastrointestinal symptoms frequently settle as nutrition becomes more consistent. Psychological recovery can also bring an enormous reduction in the amount of time and emotional energy occupied by food, exercise and body image.
Some effects, however, may take longer to improve, and occasionally there can be lasting consequences. Bone density is one area where early intervention is particularly valuable because lost bone strength may not always be completely restored. Dental enamel that has been eroded through repeated vomiting also cannot regenerate naturally.
This is not intended to frighten people into treatment. Rather, it is a reason not to wait until an eating disorder looks “serious enough” before asking for help.
When do eating disorder symptoms need urgent medical attention?
Eating disorders can sometimes cause acute medical problems. Symptoms such as fainting or collapse, chest pain, significant shortness of breath, severe weakness or confusion, blood in vomit, severe dehydration, or concerning changes in heart rate can require urgent medical assessment.
Significant electrolyte abnormalities, rapid deterioration in physical health or an inability to maintain adequate nutrition or fluids can also mean that a higher level of medical care is needed.
Similarly, if somebody is at immediate risk of harming themselves or feels unable to keep themselves safe, urgent mental health support is required.
If you are uncertain about physical safety, seek medical advice rather than trying to judge severity from weight, diagnosis or appearance alone.
Why treating the body and mind together matters
An eating disorder cannot usually be separated neatly into a “physical bit” and a “psychological bit”.
For example, somebody may be experiencing significant anxiety around eating while also feeling bloated, nauseous or unusually full because their eating has become restricted or irregular. That physical discomfort can reinforce the fear that eating is making things worse. Eating less then has further effects on nutrition, concentration, mood and anxiety, making it harder to challenge the eating disorder.
This is why specialist treatment often needs to consider physical health, nutrition and psychological wellbeing together.
At The London Centre for Eating Disorders and Body Image (TLC), treatment is tailored to the individual. A psychologist or therapist may work with the thoughts, emotions and behaviours maintaining the eating disorder, while a specialist dietitian can support nutritional rehabilitation and help someone understand and manage difficult physical symptoms. Where needed, a psychiatrist can assess psychiatric and medical risk, medication and co-occurring difficulties. We can also liaise with GPs and other medical professionals where physical monitoring or investigations are required.
Not everybody needs all of these professionals involved. For some people, weekly psychological therapy may be sufficient; others may benefit from psychology and dietetics working closely together, or from additional psychiatric oversight. The important thing is that physical and psychological difficulties are understood as part of the same picture, rather than being treated in isolation.
Frequently asked questions
What physical health effects can eating disorders cause, in the short and longer term?
Eating disorders can affect cardiovascular health, digestion, hydration and electrolyte balance, hormones, fertility, bone density, dental health, sleep, energy and concentration. The exact effects depend on the individual and their eating disorder behaviours. Significant medical complications can occur across different eating disorder diagnoses and body sizes, so appearance alone is not a reliable indication of physical risk.
What are the emotional and psychological effects that tend to accompany the physical ones?
Common effects include anxiety, low mood, shame, social withdrawal, reduced self-esteem, obsessive thinking and increasing preoccupation with food, weight or body image. Malnutrition itself can also affect concentration, emotional regulation and cognitive flexibility.
Some people have co-occurring difficulties such as OCD, ADHD, autism, trauma-related difficulties, depression or anxiety. These may interact with the eating disorder but should not automatically be assumed to be caused by it.
How does specialist MDT care address the physical and psychological effects together, rather than treating eating behaviour in isolation?
Specialist multidisciplinary treatment allows the different parts of an eating disorder to be considered together. Depending on the person’s needs, this might include psychological therapy, specialist dietetic support, psychiatric input and medical monitoring through their GP or another medical service.
Eating disorders can have significant effects on both physical and emotional health, but many of these effects can improve substantially with appropriate treatment. You do not need to wait until someone looks physically unwell, reaches a particular weight or has been struggling for a certain length of time before seeking help. If eating, food, exercise or body image is beginning to affect someone’s health or their ability to live their life, that is enough reason to ask for support.
