My gf is trying to lose some weight. She has made some progress, but she hasn't made enough changes to her diet and exercise routine. Her progress has been somewhat slow, although she has lost some weight.

How do I encourage and/or push her to lose weight faster?

I don't know if it matters, but she has admitted that I am a very high value man, and she has said that she wishes that we would get married in the future.

Thanks