Diagnosis of eating disorders is a process that begins with acceptance of its presence. Often the patient needs to be convinced of its presence as there is severe denial and resistance to the problem.
There are too many patients that diagnose themselves as being allergic to gluten or carbohydrates and resort to restrictive diets. In addition, when diagnosed in children, parents often perceive it as a parental failure and there are multiple factors that influence the detection of eating disorders.
Diagnosis involves:
Interview based tests
Medical interviews with a supportive companion (preferred) are the initial steps in diagnosis. The physician tries to find out additional information on the patient's eating history. The interviews use various questionnaires to assess the patients.
The Eating Disorders Examination (EDE), which is an interview of the patient by the doctor, and the self-reported Eating Disorders Examination-Questionnaire (EDE-Q) are both considered valid tests.
Another test is called the SCOFF questionnaire, which can help identify both very young and adult patients who meet the full criteria for anorexia or bulimia nervosa.
| Eating Disorder Specific Psychometric Tests |
| Eating Attitudes Test |
SCOFF questionnaire |
| Body Attitudes Test |
Body Attitudes Questionnaire |
| Eating Disorder Inventory |
Eating Disorder Examination Interview |
Screening questionnaire
A screening questionnaire is first applied:
- How many diets have you been on in the past year?
- Do you think you should be dieting?
- Are you dissatisfied with your body size?
- Does your weight affect the way you think about yourself?
A positive response to any of these questions warrants further evaluation
SCOFF questionnaire
Broadly the SCOFF Questionnaire includes questions like:
- Do you make yourself sick because you feel uncomfortably full?
- Do you worry you have lost control over how much you eat?
- Have you recently lost more than one stone's worth of weight (14 pounds or 6.4kg) in a 3-month period?
- Do you believe yourself to be Fat when others say you are too thin?
- Would you say that food dominates your life?
One point for every yes answer; a score 2 indicates a likely case of anorexia nervosa or bulimia nervosa
Bulimia diagnosis
For bulimia diagnosis there has to be at least two bulimic episodes per week for 3 months. Since there may be dental and gum related problems in bulimic patients dentists and oral pathologists may also help in diagnosis.
Anorexia nervosa diagnosis
For diagnosis of anorexia nervosa the criteria are patients refusal to maintain a body weight normal for age and height and an intense and irrational fear of becoming fat even though underweight. Patients typically have a distorted self-image that results in diminished self-confidence and do not accept that fact that they may be seriously emaciated and ill.
There is in addition loss of menstrual function for at least 3 months. Once detected, anorexia may be categorized further. Some have restrictive anorexia nervosa who practice severe dieting only while other may have Anorexia bulimia who have binge-purge behaviour.
Medical tests for complications
Medical tests are advised to detect and rule out complications of eating disorders. Tests should include:
| Medical Tests used in the Diagnosis and Assessment of Eating Disorders |
| 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 |
| ELISA |
Various subtypes of ELISA used to test for antibodies to various viruses and bacteria such as Borrelia burgdoferi (Lyme Disease) |
| Western Blot Analysis |
Used to confirm the preliminary results of the ELISA |
| 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 bodies' ability to metabolize glucose. Can be useful in detecting various disorders such as diabetes, an insulinoma, Cushing's Syndrome, hypoglycemia and polycystic ovary syndrome |
| Secritin-CCK Test |
Used to assess function of pancreas and gall bladder |
| 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, 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 hypothalumus. Central 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 used primarily 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. High BUN/creatinine ratio can occur in severe hydration, acute kidney failure, congestive heart failure, intestinal bleeding. A low BUN/creatinine can indicate a low protein diet, celiac disease rhabdomyolysis, cirrhosis of the liver. |
| echocardiogram |
utilizes ultrasound to create a moving picture of the heart to assess function |
| electrocardiogram (EKG or ECG |
measures electrical activity of heart can be used to detect various disorders such as hyperkalemia |
| electroencephalogram (EEG) |
measures the electrical activity of the brain. Can be used to detect abnormalities such as those associated with pituitary tumors |
| Upper GI Series |
test used to assess gastrointestinal problems of the middle and upper intestinal tract |
| Thyroid Screen TSH, t4, t3 |
test used to assess thyroid functioning by checking levels of thyroid-stimulating hormone (TSH), thyroxine (T4), and triiodothyronine (T3) |
| Parathyroid hormone (PTH) test |
tests the functioning of the parathyroid by measuring the amount of(PTH) in the blood. Test is used to diagnose parahypothyroidism. PTH also controls the levels of calcium and phosphorus in the blood (homeostasis). |
| barium enema |
an x-ray examination of the lower gastrointestinal tract |
Differential Diagnosis
Other disorders that mimic eating disorders include:
- Hyperthyroidism – overactive thyroid
- Cancers
- Inflammatory bowel disease like Crohn’s disease and ulcerative colitis
- Immunodeficiency and AIDS like states
- Chronic infections
- Malabsorption syndromes
- Addison's disease
- Diabetes
Co-existing diseases
Some diseases commonly co-exist among patients with eating disorders. These include:
- Depression - Major depression is the most common comorbid condition among patients with anorexia
- Anxiety disorders - Anxiety disorders, especially social phobia, also are common
- Obsessive-compulsive disorder – This has a prevalence of 30 percent among patients with eating disorders
- Substance abuse – This has prevalence is estimated at 12 to 18 percent in patients with anorexia and 30 to 70 percent in patients with bulimia
- Schizophrenia
Further Reading
Researchers propose ketogenic diet as a novel treatment for anorexia nervosa