<human>: Can you succinctly summarize the text in 1-3 sentences?

I have been friends with her since our college years and she has always been a bigger girl. Truly, she has a body shape that would always be described as curvy or maybe even chubby.  On the other hand, I'm a naturally slim person (though I do work out 4-5 times a week and eat mostly very healthy with the occasional indulgence).

She is about 5'5" and I'm guessing weighs 180lbs.
She is gaining more weight and has been for some time. Ie, dresses she bought last summer couldn't fit her this summer. She is addicted to diet pepsi and probably drinks 2-3 large glasses every evening (That I can see, who knows what she drinks during the day). She also eats chips or buttered popcorn, or something similar every single night. Her meals are usually some kind of meat, with potatoes and a mac and cheese or a lipton "sidekicks" thing. Rarely does she touch a salad or have a piece of fruit.

I've also noticed some hygiene stuff.. she never washes her hands after using the toilet, and she never brushes her teeth before bed. 

Anyways, she regularly makes remarks putting herself down about her weight, calling herself fat, etc. I never know what to say in these moments.. I try to tell her it's in her head, but the truth is she is right. She is too big, and is only getting bigger, and it's due to her inactivity and poor food choices. As a friend, I'm worried for her health (Esp with things like the teeth brushing). I'd really like to see her make some positive changes, but I'm not sure how (or if) I should bring this up to her, especially since she's always complaining about her size.
<bot>: Roommate makes very unhealthy choices, has some hygiene issues, and complains about her weight regularly. Do I say that I think she needs to make some lifestyle improvements, or let her realize this on her own?