Study estimates 18.1 million people lived with anorexia or bulimia in 2023

A person can appear healthy and still be seriously ill with an eating disorder. Someone who never reaches treatment can also remain absent from healthcare records without their illness disappearing. Both facts matter when interpreting a new estimate of how many people are affected. The US National Institute of Mental Health explains that eating disorders affect people across body sizes and that recovery with treatment is possible.

An estimated 18.1 million people worldwide lived with anorexia or bulimia in 2023, a 71% increase since 1990, according to ABC’s October 29 report on research in JAMA Psychiatry. The findings describe estimated illness through 2023; they are not a tally of diagnoses made this year.

The research belongs to the Global Burden of Disease project. ABC reports that researchers use population surveys rather than relying on treatment records, aiming to include people who have not accessed care. That addresses a question clinic activity alone cannot answer: how much illness exists across the population, including beyond the health system’s reach.

Three kinds of number do different jobs:

Age adjustment is useful general background for reading health statistics. The CDC explains that researchers apply rates within age groups to a standard population. The result is a comparative index rather than an observed headcount.

Imagine a population growing while the proportion affected within every age group stays unchanged. The number of people needing care can still rise. A changing age mix can also alter the total when illness is more common at some ages. Consequently, the reported 71% increase in cases does not establish a 71% increase in an individual’s likelihood of illness.

Australia had the highest estimated rate in ABC’s account, at 1,026.5 per 100,000 people. But differences in the underlying evidence complicate that ranking.

In ABC’s October 29 reporting, study senior author Damian Santomauro, a University of Queensland epidemiologist, said Australian surveys generally used a different methodology from those elsewhere. He thought this might partly explain the high estimate, although not entirely. Butterfly Helpline clinical psychologist Sarah Cox suggested that Australia’s greater research and data might also make the problem more visible. ABC reported limited information from some low-income countries. Adjusting for age would not, by itself, resolve differences in survey methods or gaps in evidence.

There is another important boundary around the headline: 18.1 million is not an estimate of all eating disorders. It covers anorexia and bulimia, leaving other diagnoses outside the total.

Those include binge-eating disorder and avoidant/restrictive food intake disorder, or ARFID. The latter can involve limiting food because of anxiety about eating or aversion to characteristics such as texture. NIMH’s overview describes these conditions and their potentially serious consequences. Someone’s need for care does not depend on whether their diagnosis appears in this particular study.

The rising count also cannot establish what caused the increase. NIMH describes eating disorders as involving a combination of genetic, biological, behavioral, psychological and social factors, with their exact causes incompletely understood.

For people seeking treatment, the gap between illness and recorded care has concrete obstacles. Cox told ABC that cost, living in regional areas and stigma can impede access. NIMH describes treatment as potentially combining psychological support, medical care and monitoring, and nutritional counseling. Early detection and treatment matter for recovery. It recommends that people concerned about their eating behavior or mental health speak with a primary care provider; looking healthy is no guarantee that someone is well.