Eating Disorders

What an eating disorder is

Eating disorders are not choices or phases. They arise from a mix of genetic vulnerability, brain biology, personality traits such as perfectionism and anxiety, and environmental pressures such as dieting, weight stigma, bullying and trauma. Twin studies suggest genes account for roughly half of the risk for anorexia and bulimia.

Once established, the behaviors become self-sustaining. Starvation itself changes brain chemistry, increases anxiety and rigidity around food, and makes it harder to eat. Bingeing and purging form a cycle that each feeds the other.

Types of eating disorders

Other feeding disorders include pica (eating non-food items such as dirt, ice or paper) and rumination syndrome (effortless regurgitation of recently eaten food).

Warning signs of an eating disorder

Behavioral signs

• Dieting, skipping meals, or cutting out whole food groups
• Rituals such as cutting food into tiny pieces or eating very slowly
• Eating in secret, hiding food, or large amounts of food disappearing
• Going to the bathroom right after meals
• Exercising compulsively, including when ill or injured
• Frequent body checking, weighing or mirror avoidance
• Withdrawal from friends and activities involving food

Physical signs

• Noticeable weight loss, weight fluctuation, or failure to grow in a child
• Periods becoming irregular or stopping
• Dizziness, fainting, feeling cold, fatigue
• Thin hair, dry skin, fine downy body hair (lanugo)
• Calluses on the knuckles from inducing vomiting
• Swollen cheeks (salivary glands) and dental erosion
• Constipation, bloating and reflux

Emotional signs

• Intense fear of gaining weight
• Self-worth tied mainly to body shape or weight
• Anxiety, low mood and irritability around mealtimes
• Denial that anything is wrong

You cannot tell by looking at someone whether they have an eating disorder. Most people with eating disorders are not underweight.

Who is at risk

• Teens and young adults, though onset in childhood and midlife is increasingly recognized
• Women and girls more often, but boys and men account for a substantial minority and are less often diagnosed
• People with a family history of eating disorders, anxiety, depression or obsessive-compulsive disorder
• People with type 1 diabetes (some restrict insulin to lose weight)
• Athletes in sports focused on weight or appearance, such as gymnastics, dance, running and wrestling
• People with a history of dieting, weight-related teasing or trauma
• Autistic people, especially for anorexia and ARFID

Health effects

Eating disorders affect nearly every organ:

• Heart: slow heart rate, low blood pressure, rhythm disturbances, heart muscle loss
• Bones: osteoporosis and fractures, which may be permanent if bone loss occurs during the teen years
• Hormones: loss of periods, infertility, low testosterone
• Electrolytes: low potassium, sodium and phosphate from purging or refeeding, which can cause fatal heart rhythms
• Gut: delayed stomach emptying, constipation, and rarely stomach rupture after a binge
• Brain: poor concentration, low mood and brain volume loss, which largely recovers with weight restoration

How eating disorders are diagnosed

A doctor or mental health professional asks about eating habits, weight history, compensatory behaviors and thoughts about body image. Screening tools such as the SCOFF questionnaire can help. A medical assessment then checks safety:

• weight, height and growth charts in children
• heart rate and blood pressure lying and standing, and temperature
• blood tests for electrolytes, phosphate, magnesium, glucose, kidney and liver function, and blood counts
• an ECG, especially with low weight or purging
• bone density scan if periods have stopped for 6 months or more

Treatment

Psychological treatment

• Family-based treatment (FBT): the first-line approach for children and teens with anorexia or bulimia. Parents take charge of meals at first, then hand control back gradually.
• Enhanced CBT (CBT-E): effective for bulimia, binge eating disorder and adult anorexia.
• Other options for anorexia in adults include MANTRA and specialist supportive clinical management.
• CBT for ARFID focuses on gradual exposure to feared foods.

Nutrition and medical care

• A dietitian helps establish regular meals and restore weight or nutrition.
• In severe malnutrition, refeeding is done carefully with blood monitoring to prevent refeeding syndrome, a dangerous shift of electrolytes.
• Hospital admission is needed for unstable vital signs, very low weight, severe electrolyte problems or suicide risk.

Medicines

• Fluoxetine can reduce binge-purge episodes in bulimia.
• Lisdexamfetamine is FDA-approved for moderate to severe binge eating disorder in adults.
• No medicine treats anorexia directly, though medicines may help coexisting anxiety or depression.

Levels of care

Treatment ranges from outpatient therapy to intensive outpatient, partial hospitalization (day programs), residential treatment and inpatient care, depending on medical risk and progress.

Outlook

Many people make a full recovery, particularly when treatment starts early. Recovery often takes years and setbacks are common. Ongoing support after weight restoration lowers the chance of relapse.

Frequently asked questions

What are the most common eating disorders?

Binge eating disorder is the most common in adults. Anorexia nervosa and bulimia nervosa are less common but well known. ARFID is increasingly diagnosed, especially in children. Many people have OSFED, a significant eating disorder that does not fit neatly into one category.

What are the early signs of an eating disorder?

Early signs include new dieting or cutting out food groups, skipping meals, preoccupation with calories or body shape, going to the bathroom after meals, compulsive exercise, secret eating, and withdrawal from social meals. Weight loss, missed periods and dizziness may follow.

Can you have an eating disorder at a normal weight?

Yes. Most people with eating disorders are not underweight. Bulimia, binge eating disorder and atypical anorexia usually occur at normal or higher weights, yet they still carry serious medical risks such as heart rhythm problems and low potassium.

How do I help someone with an eating disorder?

Choose a calm, private moment, describe specific behaviors you have noticed, and express concern without commenting on weight or appearance. Expect denial. Encourage a visit to a doctor and offer to go along. For a child or teen, contact their pediatrician promptly.

What is ARFID?

ARFID (avoidant/restrictive food intake disorder) is restricted eating driven by sensory sensitivity, fear of choking or vomiting, or low interest in food, rather than worry about weight or body shape. It can cause weight loss, poor growth and nutritional deficiencies, and is treated with specialist CBT and nutrition support.