The diagnostic workup typically includes complete medical and psychosocial history and follows a rational and formulaic approach to the diagnosis. Neuroimaging using fMRI, MRI, PET and SPECT scans have been used to detect cases in which a lesion, tumor or other organic condition has been either the sole causative or contributory factor in an eating disorder. "Right frontal intracerebral lesions with their close relationship to the limbic system could be causative for eating disorders, we therefore recommend performing a cranial MRI in all patients with suspected eating disorders" (Trummer M "et al." 2002), "intracranial pathology should also be considered however certain is the diagnosis of early-onset anorexia nervosa. Second, neuroimaging plays an important part in diagnosing early-onset anorexia nervosa, both from a clinical and a research prospective".(O'Brien "et al." 2001).

The initial diagnosis should be made by a competent medical professional. "The medical history is the most powerful tool for diagnosing eating disorders"(American Family Physician). There are many medical disorders that mimic eating disorders and comorbid psychiatric disorders. All organic causes should be ruled out prior to a diagnosis of an eating disorder or any other psychiatric disorder. In the past 30 years eating disorders have become increasingly conspicuous and it is uncertain whether the changes in presentation reflect a true increase. Anorexia nervosa and bulimia nervosa are the most clearly defined subgroups of a wider range of eating disorders. Many patients present with subthreshold expressions of the two main diagnoses: others with different patterns and symptoms.

Previously considered a topic for further research exploration, binge eating disorder was included in the "Diagnostic and Statistical Manual of Mental Disorders" in 2013. Until 2013, binge eating disorder was categorized as an Eating Disorder Not Otherwise Specified, an umbrella category for eating disorders that don't fall under the categories for anorexia nervosa or bulimia nervosa. Because it was not a recognized psychiatric disorder in the "DSM-IV" until 2013, it has been difficult to obtain insurance reimbursement for treatments. The disorder now has its own category under "DSM-5", which outlines the signs and symptoms that must be present to classify a person's behavior as binge eating disorder. Studies have confirmed the high predictive value of these criteria for diagnosing BED.

According to DSM-5, the following criteria must be present to make a diagnosis of binge eating disorder. Studies have confirmed the high predictive value of these criteria for diagnosing BED.

A. Recurrent episodes of binge eating. An episode of binge eating is characterized by both of the following:

1. Eating, in a discrete period of time (e.g., within any 2-hour period), an amount of food that is definitely larger than what most people would eat in a similar period of time under similar circumstances.

2. A sense of lack of control over eating during the episode (e.g., a feeling that one cannot stop eating or control what or how much one is eating).

B. The binge-eating episodes are associated with three (or more) of the following:

1. Eating much more rapidly than normal.

2. Eating until feeling uncomfortably full.

3. Eating large amounts of food when not feeling physically hungry.

4. Eating alone because of feeling embarrassed by how much one is eating.

5. Feeling disgusted with oneself, depressed, or very guilty afterward.

C. Marked distress regarding binge eating is present.

D. The binge eating occurs, on average, at least once a week for 3 months.

E. The binge eating is not associated with the recurrent use of inappropriate compensatory behavior as in bulimia nervosa and does not occur exclusively during the course of bulimia nervosa or anorexia nervosa.

The 2017 update to the American version of the ICD-10 includes BED under F50.81. ICD-11 may contain a dedicated entry (6B62), defining BED as frequent, recurrent episodes of binge eating (once a week or more over a period of several months) which are not regularly followed by inappropriate compensatory behaviors aimed at preventing weight gain.

Medical tests to check for signs of physical deterioration in anorexia nervosa may be performed by a general physician or psychiatrist, including:

- Complete Blood Count (CBC): a test of the white blood cells, red blood cells and platelets used to assess the presence of various disorders such as leukocytosis, leukopenia, thrombocytosis and anemia which may result from malnutrition.

- Urinalysis: a variety of tests performed on the urine used in the diagnosis of medical disorders, to test for substance abuse, and as an indicator of overall health

- Chem-20: Chem-20 also known as SMA-20 a group of twenty separate chemical tests performed on blood serum. Tests include cholesterol, protein and electrolytes such as potassium, chlorine and sodium and tests specific to liver and kidney function.

- Glucose tolerance test: Oral glucose tolerance test (OGTT) used to assess the body's ability to metabolize glucose. Can be useful in detecting various disorders such as diabetes, an insulinoma, Cushing's Syndrome, hypoglycemia and polycystic ovary syndrome.

- Serum cholinesterase test: a test of liver enzymes (acetylcholinesterase and pseudocholinesterase) useful as a test of liver function and to assess the effects of malnutrition.

- Liver Function Test: A series of tests used to assess liver function some of the tests are also used in the assessment of malnutrition, protein deficiency, kidney function, bleeding disorders, and Crohn's Disease.

- Lh response to GnRH: Luteinizing hormone (Lh) response to gonadotropin-releasing hormone (GnRH): Tests the pituitary glands' response to GnRh a hormone produced in the hypothalamus. Hypogonadism is often seen in anorexia nervosa cases.

- Creatine Kinase Test (CK-Test): measures the circulating blood levels of creatine kinase an enzyme found in the heart (CK-MB), brain (CK-BB) and skeletal muscle (CK-MM).

- Blood urea nitrogen (BUN) test: urea nitrogen is the byproduct of protein metabolism first formed in the liver then removed from the body by the kidneys. The BUN test is primarily used to test kidney function. A low BUN level may indicate the effects of malnutrition.

- BUN-to-creatinine ratio: A BUN to creatinine ratio is used to predict various conditions. A high BUN/creatinine ratio can occur in severe hydration, acute kidney failure, congestive heart failure, and intestinal bleeding. A low BUN/creatinine ratio can indicate a low protein diet, celiac disease, rhabdomyolysis, or cirrhosis of the liver.

- Electrocardiogram (EKG or ECG): measures electrical activity of the heart. It can be used to detect various disorders such as hyperkalemia

- Electroencephalogram (EEG): measures the electrical activity of the brain. It can be used to detect abnormalities such as those associated with pituitary tumors.

- Thyroid Screen TSH, t4, t3 :test used to assess thyroid functioning by checking levels of thyroid-stimulating hormone (TSH), thyroxine (T4), and triiodothyronine (T3)

A variety of medical and psychological conditions have been misdiagnosed as anorexia nervosa; in some cases the correct diagnosis was not made for more than ten years.

The distinction between the diagnoses of anorexia nervosa, bulimia nervosa and eating disorder not otherwise specified (EDNOS) is often difficult to make as there is considerable overlap between people diagnosed with these conditions. Seemingly minor changes in a people's overall behavior or attitude can change a diagnosis from anorexia: binge-eating type to bulimia nervosa. A main factor differentiating binge-purge anorexia from bulimia is the gap in physical weight. Someone with bulimia nervosa is ordinarily at a healthy weight, or slightly overweight. Someone with binge-purge anorexia is commonly underweight. People with the binge-purging subtype of AN may be significantly underweight and typically do not binge-eat large amounts of food, yet they purge the small amount of food they eat. In contrast, those with bulimia nervosa tend to be at normal weight or overweight and binge large amounts of food. It is not unusual for a person with an eating disorder to "move through" various diagnoses as their behavior and beliefs change over time.

For the purpose of identifying an alcohol use disorder when assessing binge drinking, using a time frame of the past 6 months eliminates false negatives. For example, it has been found that using a narrow 2 week window for assessment of binge drinking habits leads to 30 percent of heavy regular binge drinkers wrongly being classed as not having an alcohol use disorder. However, the same researchers also note that recall bias is somewhat enhanced when longer timeframes are used.

There are two main types of treatment given to those suffering with bulimia nervosa; psychopharmacological and psychosocial treatments.

Binge drinking is considered harmful, regardless of a person's age, and there have been calls for healthcare professionals to give increased attention to their patients drinking habits, especially binge drinking. Some researchers believe that raising the legal drinking age and screening brief interventions by healthcare providers are the most effective means of reducing morbidity and mortality rates associated with binge drinking. Programs in the United States have thought of numerous ways to help prevent binge drinking. The Centers for Disease Control and Prevention suggests increasing the cost of alcohol or the excise taxes, restricting the number of stores who may obtain a license to sell liquor (reducing "outlet density"), and implementing stricter law enforcement of underage drinking laws. There are also a number of individual counseling approaches, such as motivational interviewing and cognitive behavioral approaches, that have been shown to reduce drinking among heavy drinking college students. In 2006, the Wisconsin Initiative to Promote Healthy Lifestyles implemented a program that helps primary care physicians identify and address binge drinking problems in patients. In August 2008, a group of college presidents calling itself the Amethyst Initiative asserted that lowering the legal drinking age to 18 (presumably) was one way to curb the "culture of dangerous binge drinking" among college students. This idea is currently the subject of controversy. Proponents argue that the 21 law forces drinking underground and makes it more dangerous than it has to be, while opponents have claimed that lowering the age would only make the situation worse. Despite health warnings, most Australian women drink at least one night a week. But experts are warning they are not only damaging their bodies but are also at risk of attracting sexual predators.

Some researchers have also claimed positive outcomes in hypnotherapy.

Cognitive behavioural therapy, individual therapy, and group therapy are often beneficial in helping people keep track of their eating habits and changing the way they cope with difficult situations.

There are several 12-step programs that helps overeaters, such as Overeaters Anonymous or Food Addicts in Recovery Anonymous and others.

It is quite clear through research, and various studies that overeating causes addictive behaviors.

In some instances, overeating has been linked to the use of medications known as dopamine agonists, such as pramipexole.

According to the National Eating Disorder Information Centre (NEDIC), the first step for someone going through anorexia athletica is to realize their eating and exercise habits are hurting them. Once an individual has realized they have a disorder, an appointment should be made with the family doctor. A family doctor can advise further medical attention if needed. With sports anorexia, it is important to go to a dietitian as well as a personal trainer. People with sports anorexia need to learn the balance between exercise and caloric intake.

Few studies to date have examined OSFED prevalence. The largest community study is by Stice (2013), who examined 496 adolescent females who completed annual diagnostic interviews over 8 years. Lifetime prevalence by age 20 for OSFED overall was 11.5%. 2.8% had atypical AN, 4.4% had subthreshold BN, 3.6% had subthreshold BED, and 3.4% had purging disorder. Peak age of onset for OSFED was 18–20 years. NES was not assessed in this study, but estimates from other studies suggest that it presents in 1% of the general population.

A few studies have compared the prevalence of EDNOS and OSFED and found that though the prevalence of atypical eating disorders decreased with the new classification system, the prevalence still remains high. For example, in a population of 215 young patients presenting for ED treatment, the diagnosis of EDNOS to OSFED decreased from 62.3% to 32.6%. In another study of 240 females in the U.S. with a lifetime history of an eating disorder, the prevalence changed from 67.9% EDNOS to 53.3% OSFED. Although the prevalence appears to reduce when using the categorizations of EDNOS vs. OSFED, a high proportion of cases still receive diagnoses of atypical eating disorders, which creates difficulties in communication, treatment planning, and basic research.

In individuals with autism, schizophrenia, and certain physical disorders (such as Kleine-Levin syndrome), nonnutritive substances may be eaten. In such instances, pica should not be noted as an additional diagnosis.

Food addiction impacts relationships, especially those within the family. This is because the person with the addiction is vastly more involved with food than with people – it becomes their safest, most important and meaningful relationship. Other connections to friends and family take a back seat. This often leads to a deep sense of isolation from others.

There is no single test that confirms pica. However, because pica can occur in people who have lower than normal nutrient levels and poor nutrition (malnutrition), the health care provider should test blood levels of iron and zinc.

Hemoglobin can also be checked to test for anemia. Lead levels should always be checked in children who may have eaten paint or objects covered in lead-paint dust. The health care provider should test for infection if the person has been eating contaminated soil or animal waste. The Diagnostic and Statistical Manual of Mental Disorders, 5th edition, posits four criteria that must be met for a person to be diagnosed with Pica:

Clinicians will often follow a diagnostic checklist to test whether or not an individual is exhibiting behaviors and characteristics that may lead to a diagnosis of ARFID. Clinicians will look at the variety of foods an individual consumes, as well as the portion size of accepted foods. They will also question how long the avoidance or refusal of particular foods has lasted, and if there are any associated medical concerns, such as malnutrition. Unlike most eating disorders, there may be a higher rate of ARFID in young boys, than there is in young girls.

Drunkorexia is not a medically diagnosed disorder therefore there is no specific treatment. However, as drunkorexia is a combination of two different disorders, binge drinking and eating disorders such as anorexia and bulimia the treatment will need to address both.

Rather than providing specific diagnostic criteria for EDNOS, the fourth revision of the "Diagnostic and Statistical Manual of Mental Disorders" ("DSM-IV") listed six non-exhaustive example presentations, including individuals who:

1. Meet all criteria for anorexia nervosa except their weight falls within the normal range

2. Meet all criteria for bulimia nervosa except they engage in binge eating or purging behaviors less than twice per week or for fewer than three months

3. Purge after eating small amounts of food while retaining a normal body weight

4. Repeatedly chew and spit out large amounts of food without swallowing

5. Do not meet criteria for binge eating disorder

Despite its subclinical status in "DSM-IV", available data suggest that EDNOS is no less severe than the officially recognized "DSM-IV" eating disorders. In a comprehensive meta-analysis of 125 studies, individuals with EDNOS exhibited similar levels of eating pathology and general psychopathology to those with anorexia nervosa and binge eating disorder, and similar levels of physical health problems as those with anorexia nervosa. Although individuals with bulimia nervosa scored significantly higher than those with EDNOS on measures of eating pathology and general psychopathology, those with EDNOS exhibited more physical health problems than those with bulimia nervosa.

Few studies guide the treatment of individuals with OSFED. However, cognitive behavioral therapy (CBT), which focuses on the interplay between thoughts, feelings, and behaviors, has been shown to be the leading evidence-based treatment for the eating disorders of BN and BED. For OSFED, a particular cognitive behavioral treatment can be used called CBT-Enhanced (CBT-E), which was designed to treat all forms of eating disorders. This method focuses not only what is thought to be the central cognitive disturbance in eating disorders (i.e., over-evaluation of eating, shape, and weight), but also on modifying the mechanisms that sustain eating disorder psychopathology, such as perfectionism, core low self-esteem, mood intolerance, and interpersonal difficulties. CBT-E showed effectiveness in two studies (total N = 219) and well maintained over 60-week follow-up periods. CBT-E is not specific to individual types of eating disorders but is based on the concept that common mechanisms are involved in the persistence of atypical eating disorders, AN, and BN.

Although EDNOS (formerly called atypical eating disorder) was originally introduced in "DSM-III" to capture unusual cases, it accounts for up to 60% of cases in eating disorder specialty clinics. EDNOS is an especially prevalent category in populations that have received inadequate research attention such as young children, males, ethnic minorities, and non-Western groups.

A review on behavioral addictions listed the estimated the lifetime prevalence rate (i.e., the proportion of individuals in the population that developed the disorder during their lifetime) for food addiction in the United States as 2.8%.

Typically the eating is done rapidly and a person will feel emotionally numb and unable to stop eating.

Most people who have eating binges try to hide this behavior from others, and often feel ashamed about being overweight or depressed about their overeating. Although people who do not have any eating disorder may occasionally experience episodes of overeating, frequent binge eating is often a symptom of an eating disorder.

Binge-eating disorder, as the name implies, is characterized by uncontrollable, excessive eating, followed by feelings of shame and guilt. Unlike those with bulimia, those with binge-eating disorder symptoms typically do not purge their food, fast, or excessively exercise to compensate for binges. Additionally, these individuals tend to diet more often, enroll in weight-control programs and have a history of family obesity. However, many who have bulimia also have binge-eating disorder.

→Swollen of salivary glands lead to the change of facial shape

→If gastric juice is flown to the esophagus constantly, it will lead to a corrosion of the wall of esophagus(long term harmful effect)

→If gastric juice is flown to the oral cavity, it will lead to a corrosion of the oral tissue, dissolve the enamel and consequently cause the loss of teeth/increase chances for tooth decay

Drunkorexia consists of 3 major aspects: alcohol use/abuse, food intake restriction, and excessive physical activity. It is commonly summarised in the following activities:

- Counting daily calorie intake (commonly known as "calorie counting") to ensure no weight will be gained when consuming alcohol.

- Missing or skipping meals to conserve calories for consumption of alcoholic beverages.

- Over exercising to counterweigh for calories consumed from alcoholic beverages.

- Consuming an extreme amount of alcohol to vomit previously digested food.

Binge eating is a pattern of disordered eating which consists of episodes of uncontrollable eating. It is sometimes a symptom of binge eating disorder or compulsive overeating disorder. During such binges, a person rapidly consumes an excessive quantity of food. A diagnosis of binge eating is associated with feelings of loss of control.