SUBREDDIT: r/relationships
TITLE: Me [19 M] with my girlfriend [19 F] of 7 months, would like her to be more active.
POST: My girlfriend who I meet in college has started to put on some weight. She played a varsity sport but decided to quit. I supported her choice to quit but advised she should still workout. I'm very much into staying in shape and eating right. I offer to run with her, and go on hikes with her. She comes with me because I like to, but she does turn down her friends who offer. I want to know what are some ways I can get her to be active and kick some of that weight off. I love her dearly and don't plan on leaving her over this I just care about her health
TL;DR: 
Girlfriend quit playing a sport and isn't nearly as active anymore and has put on some weight, how can I bring this to her attention?