"With great power comes great responsibility."
B eing the president of the United States, one of the superpowers of the world, come with a heavy-weighing bundle of responsibilities that can squeeze the juice out of any man. Talk about our former President, Obama. He went through his own share of changes over the period of eight years. And, it's not surprising that it vividly reflects on his physical appearance too.Here, are ten US presidents whose change in looks can give you more than enough evidence of the stressful job that a president has to be loyal to every minute that he is at service. Check them out.