Well nobody FORCED Pauline to front the advertising campaign for LiterLife. She took the money and now cannot start to complain that the media are watching her to see if she puts the weight back on. If she really wanted to shift the weight she could have done it privately.
Actually if she has lost weight "privately", she would have been subjected to speculation about whether she has had a gastric band and be expected to talk about her weight loss. This way she had some control over what was said about her.