<human>: My GF of 8 months has recently decided that she wants to eat more healthy and I told her I was 100% on board and that I would start to eat healthy too and help her whenever she needs help. 

The problem is that whenever we go to the store, she immediately goes to the chocolate/candy and wants to buy it for "snacks" at work.  I remind her that she wants to eat more healthy and that maybe yogurt or carrots are a better snack choice.  She then gets mad at me for suggesting those things and ends up buying the candy anyway.

How do I support her in her choice to eat more healthy?  I try to buy better foods when we go to the grocery store but she always seems to shut me down.  We're also not living together except when I go see her on the weekends or during the week sometimes so it's hard for me to help her when I'm not there.

Can you succinctly summarize the text in 1-3 sentences?
<bot>: How do I support my GF to eat healthier and why does she get mad at me when I do try to help?