Drupal 7 Check if Body is Empty with EntityMetadataWrapper

example.php

<?php

// Load the node and wrap it.
$node = node_load(123);
$wrap = entity_metadata_wrapper('node', $node);

// Make sure the body isn't empty, and then sanitize it.
// We use field_get_items() because we couldn't figure out how to use EMW's __isset() on the body field.
$body = field_get_items('node', $node, 'body') ?
  $wrap->body->value->value(array('sanitize' => TRUE)) : '';

drupal_set_message($body);