Body image and self-esteem are related but distinct concepts. Body image describes one’s attitude toward a single aspect of the self, namely the physical body, while self-esteem relates to one’s view of the self as a whole. Self-esteem may involve an evaluation of one’s overall worth and is generally not limited to the physical body. Nevertheless, the way people think and feel about their bodies is often strongly connected to their overall view of themselves.
A number of studies, conducted across various age groups, have consistently demonstrated a positive relationship between self-esteem and body image. In other words, higher self-esteem is linked to a more positive body image, while lower self-esteem is associated with a more negative body image. However, research has not yet determined the direction of the relationship. Body image may be lowered by poor self-esteem, but a negative body image might just as easily lead to low self-esteem. Most researchers agree both possibilities are plausible.
People with low self-esteem tend to be more critical of their own appearance and are often more likely to engage in negative comparisons of themselves with others, an action shown to increase the likelihood of body dissatisfaction. On the other hand, those who experience a more negative body image may become preoccupied with their appearance and are less likely to focus on personal strengths in other areas, which may result in a less favorable evaluation of self-worth. http://www.goodtherapy.org