Eating disorders rarely announce themselves. They develop gradually, often hidden behind excuses, routines, and behaviors that can look like health consciousness or stress. But there are specific patterns you can learn to recognize, spanning changes in how someone eats, how their body responds, and how they think and talk about themselves. Roughly 355 out of every 100,000 people worldwide live with an eating disorder, and that number has been climbing steadily since the 1990s, with the fastest growth among young adults aged 20 to 24.
Changes in Eating Behavior
The most visible signs tend to show up around food. Someone developing an eating disorder may start refusing entire food groups, cutting out all carbohydrates or fats with rigid conviction. They may develop rituals at mealtimes: eating foods in a strict order, chewing excessively, cutting food into tiny pieces, or rearranging what’s on their plate without actually eating much. These rituals often look like preferences or quirks at first, but they become inflexible over time.
Skipping meals is common, and so are the excuses that come with it. “I already ate.” “I’m not hungry.” “I’ll eat later.” The person may avoid restaurants, family dinners, or any social situation that revolves around food. When they do eat around others, portions may shrink noticeably. On the other end, someone with binge eating episodes may eat large amounts of food in a short window, often within about two hours, and feel completely unable to stop. They typically eat faster than usual, continue past the point of physical discomfort, and eat when they aren’t hungry at all. Binge episodes almost always happen in private, so what you’re more likely to notice is missing food, hidden wrappers, or a pattern of someone disappearing after meals.
Some people create structured routines specifically to accommodate these behaviors, blocking out time when they won’t be observed. Others swing between extremes: strict fasting followed by uncontrolled eating, or periods of rigid “clean eating” that suddenly collapse.
Physical Signs to Watch For
The body can’t hide prolonged malnutrition or purging, even when behavior stays secret. Someone restricting food heavily may develop fine, downy hair on their arms, face, or back. This is the body’s attempt to insulate itself when it doesn’t have enough energy to maintain normal temperature. You might also notice dry skin, brittle nails, hair thinning or falling out, and a person who’s always cold.
Purging leaves its own marks. Repeated vomiting erodes tooth enamel, particularly on the backs of the front teeth, and can cause swollen salivary glands that give the jaw a puffy appearance. Calluses or scars on the knuckles, from contact with the teeth during self-induced vomiting, are another telltale sign. Internally, purging disrupts heart rhythm and blood pressure, and causes dehydration that may show up as fainting, dizziness, or chronic fatigue.
Sudden or significant weight changes in either direction are worth paying attention to, but weight alone is unreliable. Many people with serious eating disorders maintain a normal or higher weight.
Why Weight Can Be Misleading
One of the most common misconceptions is that someone needs to look visibly thin to have an eating disorder. Atypical anorexia involves the same dangerous restriction of food, the same fear of weight gain, and the same distorted body image, but it occurs in people who started at a higher weight. They may lose a significant amount rapidly while still appearing average or even above average. The health consequences, including heart problems, hormonal disruption, and bone loss, are just as severe. Because these individuals don’t match the stereotypical image of an eating disorder, they’re often praised for their weight loss rather than recognized as struggling.
Binge eating disorder, the most common eating disorder, also doesn’t come with an obvious physical profile. People of any size can experience the distressing cycle of compulsive overeating followed by shame and guilt. And while eating disorders have historically been associated with young white women, men are the fastest-growing demographic, and the condition affects people across all ages, races, and income levels.
Psychological and Emotional Shifts
Eating disorders reshape how a person thinks, not just how they eat. Someone may become intensely preoccupied with calories, food labels, or body measurements, spending hours each day thinking about what they’ve eaten or will eat. Body checking is common: repeatedly looking in mirrors, measuring their waist, pinching skin, or trying on clothes to assess whether their body has changed. They may ask the same questions over and over. “Do I look okay?” “Does this make me look fat?”
Self-worth becomes fused with body shape. A person may feel genuinely good about themselves only on days they perceive their body a certain way, and spiral into anxiety or depression when that perception shifts. Irritability, difficulty concentrating, and withdrawal from friends and activities they once enjoyed are all typical. Some of these mood changes are psychological, and some are directly caused by malnutrition, which alters brain chemistry and reduces the ability to regulate emotions.
Secrecy increases. The person may become defensive when asked about eating habits, wear loose clothing to hide weight changes, or pull away from relationships that might expose their behavior.
Signs Specific to Athletes
In athletes, eating disorders often hide behind the language of performance and discipline. The condition known as Relative Energy Deficiency in Sport (RED-S) occurs when an athlete consistently takes in less energy than their training demands, whether intentionally or not. The consequences ripple through nearly every body system.
Female athletes may lose their menstrual period entirely. Male athletes may experience drops in testosterone. Both are at dramatically higher risk for stress fractures, with research showing a 4.5-fold increase in bone injuries among athletes with hormonal disruption from underfueling. Performance paradoxically declines: more illness, slower recovery, impaired coordination, reduced cardiovascular function. Athletes with low energy availability are 2.4 times more likely to develop psychological issues including depression and impaired judgment.
Red flags include an athlete who trains through injuries, has rigid pre-competition eating rules, loses weight during a season when training volume is high, or shows declining performance despite increased effort. Hair loss, frequent illness, and gastrointestinal complaints are common physical signs.
When Picky Eating Becomes Something More
Avoidant/Restrictive Food Intake Disorder (ARFID) looks nothing like traditional eating disorders. There’s no fear of gaining weight, no body image distortion. Instead, a person eats from an extremely narrow range of foods, often driven by sensory sensitivity, fear of choking or vomiting, or simple lack of interest in eating. Most picky eaters don’t develop health problems from their preferences, but ARFID crosses the line when the restriction leads to weight loss, nutritional deficiencies, dependence on supplements to meet basic needs, or significant difficulty participating in normal social life because of shame or anxiety around food. People with ARFID show greater food rigidity and higher rates of anxiety and obsessive-compulsive symptoms compared to typical picky eaters.
A Quick Screening Framework
A simple five-question tool called the SCOFF questionnaire can help clarify whether someone’s relationship with food has crossed into disordered territory. The questions ask whether a person makes themselves sick because they feel uncomfortably full, whether they’ve lost control over how much they eat, whether they’ve lost more than 14 pounds in three months, whether they believe they’re fat when others say they’re thin, and whether food dominates their life. Answering yes to two or more of these five questions identified anorexia and bulimia with 100% sensitivity in clinical testing. It’s not a diagnosis, but it’s a useful way to organize concerns you might have about yourself or someone else.
How to Bring It Up
If you recognize these signs in someone you care about, how you approach the conversation matters enormously. Choose a private setting, and lead with specific observations rather than accusations. “I’ve noticed you haven’t been eating dinner with us” lands very differently than “You’re not eating.” Use “I” statements: “I’m worried because I’ve seen you skip meals all week” rather than “You have a problem.”
Point out changes beyond food when you can, things like mood shifts, social withdrawal, or declining energy, which may be easier for the person to acknowledge. Avoid offering simple fixes like “just eat more” or “just stop doing that.” These responses, however well-intentioned, leave the person feeling misunderstood and are likely to shut down the conversation. Be prepared for denial, anger, or deflection. That doesn’t mean you said the wrong thing.
Don’t make promises you can’t keep, like “I won’t tell anyone.” Be honest, be caring, and be firm. Recovery from an eating disorder is possible, but it rarely begins without someone noticing and saying something.