<human>: Could you distill the essence of the text into 1-3 sentences?

My best friend Callie is a big girl. Almost 6 feet, large hands, large head...she is big boned. She's also overweight and knows it, always has been. About a year about she had briefly tried keto and lost some weight and looked great, it was so fun comparing recipes too and it encouraged me to find /r/keto and I've also lost some weight though I have much less to lose than her.

The past year she hasn't been interested in dieting or any kind of activity (she does take her dog on a long walk a day, about 40 minutes so that's not nothing). She eats like it's going out of style. Most of our other friends are thin and diet and workout. Zero people judge Callie for being overweight. She is one of the most popular girls I know, she's hilarious and loving, and I think people would never critique her physique because she's so wonderful. 

But I'm worried about her health. She is constantly sweating and her knees seem to give constant pain. She has some non weight related health issues and sees several doctors regularly so I assume someone official has talked to her about her weight. I share my keto recipes with her, invite her to do activities not about food or drink, but I don't know at what point I could talk to her about her weight without hurting her feelings.

I brought it up to another one of our friends who just said "I think Callie is beautiful". So do I let her just keep gaining weight? She knows how to lose weight, she knows she needs to, my feeling is that she doesn't need me too telling her more than recipe ideas, but I'm worried about her...help.
<bot>: Overweight friend keeps gaining weight to the point that I'm worried about her health, but she sees medical professionals regularly so do I let them handle?