<human>: Condense the text into a few key points

I have been with my girlfriend for 3 months and she's been a joy to have and talk to. When we first met, she was of average weight, and so I couldn't have been upset. 

However, in the last month she has been putting on weight very quickly, and I believe she may have been on up to 15 or so pounds. I feel like I shouldn't find it that big of a deal, but it's driving me crazy and since I'm starting to not even find her attractive anymore. 

Does anyone have any advice in how I can reverse this situation and suggest to her to lose weight without her feeling upset or offended? If I can't find a solution to this or the weight gain continues, I really think it may lead to me breaking up with her.
<bot>: Girlfriend gaining weight and its driving me crazy. Need help in ways to fix this or telling her she should lose it.