Ariana Grande’s making a full mea culpa apologizing for calling out all Americans to make a point about obesity. We’re told Ariana’s telling people close to her she’s embarrassed about the comments she made while in the donut shop … saying she hates America and Americans. We’re told she was indeed merely reacting to the massive donuts that had just been placed in front of her but she realizes her reaction was inappropriate. Our sources say she realizes obesity is a serious issue, and she shouldn’t have made fun of it.