If you think a girl's remarks are superficial or even unhealthy, you can reply to her in some positive ways to make her realize that her words may have a bad influence on others. You can try to guide her to focus on a healthy lifestyle instead of simply slimming down. You can do the following:

Health comes first. Tell her that health is more important than appearance. If she wants to lose weight, she should do so through a healthy diet and exercise. This can not only lose weight, but also improve her physique and make her healthier.

2. self-confidence is the most beautiful. Tell her that self-confidence is the most beautiful, no matter how big or small she is, as long as she is confident, everything will look good. Let her realize that she is beautiful and doesn't need to pursue too harsh external standards.

3. Don't follow blindly. Tell her not to blindly follow the trend, but to choose a dress style that suits her and make herself feel comfortable. After all, everyone's figure and style are different, and not all popular styles are suitable for everyone.

4. Encourage her with positive words. Tell her that she is already beautiful and doesn't need to be too hard on herself. Through encouragement, let her realize that her appearance is not the only standard, and she has more advantages and charm.

In short, we should respond to girls in a positive and encouraging way to make her realize that health and self-confidence are more important than appearance. In this way, you can help her know herself better and have a healthier and more positive attitude towards life.