<human>: Can you provide a brief rundown of the text in within 3 sentences?

My friend Katie and I have been best friends for about 10 years. She is a kind, intelligent, and amazing person and because of this I've tried to overlook her hygiene issues for a long time. Lately though things have gotten worse and have led me to question whether or not this friendship is sustainable, and if so, how to approach her. 

Here are a couple of things I've noticed lately about her hygiene:

+ We live in different cities so she stays with me when she comes to my town. Last time she stayed for 4 days and didn't shower once.

+ She never brushes her teeth

+ She doesn't brush her hair or put on makeup

+ She sleeps in and wears the same hoodie 24/7. It's covered in stains and she has no desire to wash it. Sometimes she'll sleep in the same clothes that she will wear again the next day.

+ Since she doesn't shower she has a noticeable odor 

+ Her clothing and purses are in terrible condition but she doesn't want to replace them because she hates shopping.

One other major issue (somewhat related to her hygiene problem) is her diet. She's been overweight almost her entire life but that's also gotten worse in the last few months now that she works two jobs. It's to the point where I actually get nauseated watching her eat throughout the day because her diet is almost always candy, soda, and chips (if I had to guess, she consumes roughly 1000g of sugar per day). Because of her bad eating habits I usually have to cook a separate dinner for myself when she's here because I don't want to eat such unhealthy meals.

So reddit, what should I do? At this point I'm finding myself praying that we don't run into my roommates or friends because she looks so unpresentable. Are we simply incompatible as friends, or is this something that can be fixed? I've already offered to teach her healthy cooking and go to the gym with her, both to no avail. Other than her weight she is extremely happy with her life so for her this is not a major issue.
<bot>: Best friend has terrible hygiene and an extremely bad diet. It's gotten to the point where I'm embarrassed to introduce her to my other friends or be out in public with her. What do I do?