How to reply humorously when a girl talks about losing weight

In this case, you can reply like this:

1. "Okay, then I will have to call you Slim Beauty from now on, but your figure is also great now, and health is the most important thing!" : This way of replying is to transform the topic of weight loss into complimenting her current figure by pretending to misunderstand the girl’s meaning. This will not embarrass her and give her positive feedback.

2. "Haha, I remember you said you wanted to lose weight many times. I hope you can stick to it this time. However, don't forget to reward yourself with a delicious meal occasionally, so you will be more motivated!" : This way of replying shows humor by teasing the other person's determination. At the same time, I also remind you not to be too demanding on yourself, and it is equally important to maintain a balanced attitude towards life.