<human>: Hey everyone,

My girlfriend and I have been together for close to 4 years now, during that time she has progressively gained weight to the point where now she is obese. 

I have always tried to encourage her to lose it, I've suggested physical activity which she sometimes accepts but she never sticks to it. The amount of time and money she's spent on silly quick fix diets has gotten to a point where it's clear that she doesn't care about the long term, she just wants a quick fix. 

I'll be the first to say that she's lazy, but every day I encourage her. I try to motivate her to change her lifestyle but nothing ever works.

Early in our relationship she was a healthy weight and I fear that she's gotten comfortable with herself and more importantly with me, she has no motivation to lose weight. Why should she? She has a stable relationship, she sees us getting married and living together for the rest of our lives.

I've come to the realization that the best way to motivate her is to leave her, don't get me wrong, I love her with all my heart which is why I think this has to happen.

So, please convince me that there's another solution. Everytime I try to talk to her she gets angry and shuts herself off from me, it's a sensitive subject for her, it makes it difficult to do anything.

Thank you in advance.

Can you succinctly summarize the text in 1-3 sentences?
<bot>: My girlfriend has become obese in the 4 years we've been together and I think I have to leave her to motivate her to lose the weight.