You can communicate with your colleagues and tell them that although you are fat, you value being fat. You don't want to be thin, and you don't want to do high-intensity weight loss exercise every day like them, because you like your present life and you like you now.

Don't mind quitting the group without telling them, because they also pulled you in out of kindness. If you quit the group without authorization, they will have bad ideas and be embarrassed to be with them.

They are kind enough to let you lose weight with them. In fact, they also see that you are still a little fat. Although you don't admit that you don't want to lose weight, I suggest you lose weight. To lose weight, after all, it is good for you and good for your health. At the same time, you can accumulate popularity and make friends with them. Why not?

If you lose weight with them, you can do weight-loss exercises together, run together, do hi it together, and go to the gym to do strength training together. This will not only increase your muscle mass, but also reduce your fat and make your body more and more perfect. Forward and backward is not a dream.