While it is not a very commonly known fact to people, poor body image does affect our social performance. Poor body image can wreck havoc on our self-esteem; and this may reflect as shyness and anxiety in social situations. Improving one's self-concept is definitely one of the necessary steps in conquering shyness and social anxiety.

The self concept is a tricky premise, and one of the most troublesome views we have about ourselves is our body image. The more evident part of body image disturbances is related to fatness/thinness and how it reflects on our desirability and self-esteem. Research has showed that people who view themselves as "ugly", "fat", or "physically attractive" are more likely to experience social anxiety, especially when surrounded by people who they view as "ideal" or "beautiful". These people are also more prone to shyness, even as children.
Also, there are other important distortions in our body image and how it affects our social interaction.  Some people have an inherent feeling of "awkwardness"; they feel as if they are physically different, weird, or awkward especially in social situations. It might also be a feeling of general clumsiness and an inability to function, move, or talk as smoothly as other people that they label as socially apt.
And as anyone who experienced a "performance anxiety" knows, worrying about how you function actually makes you less able to function. This general feeling of clumsiness and self-consciousness about their bodies' ability to carry out simple social function, like pouring someone a drink for instance, triggers an anxiety that further perpetuates the situation and perhaps even escalates it: if they spill s few drops on the table, they may even become more withdrawn for the rest of the evening. Several experiences of that sort will perpetuate their general perception of themselves as clumsy, and this will inevitably lead to shyness and aggravate social anxiety. This feedback loop is very destructive. And while it is difficult to break the cycle, the first step to do so is alter these people's body image as means to enhance their self-perception.

A healthy body image is undeniably one of the first steps towards conquering social anxiety and shyness. It is also important to integrate this concept in your self-help or therapeutic program as you try to achieve a weight-loss goal, or a cosmetic procedure; because sometimes even changing what's on the outside cannot alter the way we view our body in our mind's eye. It is what we believe, not what other people see, that counts.