Body image (medicine)
Body image is a medical term, often used in the context of describing a patient's cognitive perception of their own body. The medical concept began with the work of the Austrian neuropsychiatrist and psychoanalyst Paul Schilder whose masterpiece The Image and Appearance of the Human Body was first published in 1935.
In psychology, it typically refers to one's perceptions, beliefs, and emotional attitudes towards one's body. The concept is used to discuss various pathologies and disorder, such as anorexia nervosa and other eating disorders, body dysmorphic disorder, body integrity identity disorder and various post-stroke conditions like somatoparaphrenia, and unilateral neglect.
Body image problems may also manifest themselves in psychopathologies like schizophrenia and the Cotard delusion. Although it is often confused with the term 'body schema', which concerns postural and motor control, 'body image' is distinct from the former phenomena.
Feel status minus Actual status Inconsistency
FAI (Feel status minus Actual status Inconsistency) index is used to assess someone’s weight perception. FAI scores range from -3 to +3: Negative FAI values mean weight status underestimation, positive FAI values mean weight status overestimation and a FAI score of 0 means a realistic perception of one’s weight status. One study found that women tend to have positive FAI values (overestimating their weight) while men had negative FAI values (underestimating their weight) 
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