Just save the size of your body in two variables while creating your body and then call the appropriate draw method. To get the position of your object call body.getPosition().
For example
Texture t = assetManager.get("your texture", Texture.class);
BodyDef bodyDef = new BodyDef();
body.type = BodyType.DynamicBody
float width = 64 * WORLD_TO_BOX;
float height = 64 * WORLD_TO_BOX;
Shape shape = new PolygonShape();
float[] points = new float[]{0,0,width,0,width,height,0, height};
shape.set(points);
FixtureDef def = new FixtureDef();
def.shape = shape;
...
body.createFixture(def);
shape.dispose();
And later when you want to draw
public void render(Spritebatch batch) {
batch.draw(t, body.getPosition().x * BOX_TO_WORLD, body.getPosition().y * BOX_TO_WORLD, width * BOX_TO_WORLD, height * BOX_TO_WORLD);
}