I think your responses might have been a little better if you didn't post two damn good looking women as examples hahaha. Especially the first one.
Personally, I like thick girls and I understand maybe you don't. Not here to judge, completely understandable.
I don't know exactly what to tell you because, well. I honestly believe there is no good way to tell a girl she NEEDS to lose weight without hurting her self-esteem, and it would probably hurt her even more thinking her looks aren't even good enough for her significant other.
1. If she is overweight enough, (I don't know how accurate those pics are, I am actually scared she might be a decent weight and you're trying to drive her to be a twig) You can start by showing concern for her HEALTH rather than looks. Maybe you can tell her that you want to last long with her, and both be healthy as possible. WITHOUT MENTIONING that you don't like her chubbiness.
2. Invite her to the gym, try to get her into the fitness mode naturally. Girls love seeing results probably more than men do. The minute she sees an improvement in her body, she will be hooked. I am pretty sure of that. (no offense to anyone)
3. I can't think of anything else at the moment :/ look, if she's
1.comfortable with how she looks,
2.she's healthy,
3. and she can at least maintain that weight and not increase constantly, then you have no place to tell a girl she NEEDS to lose weight, because she doesn't. There's no nice way to put it. Unfortunately, it's not that simple.
You can tell a girl the nicest way in the world she needs to lose weight. She might have a nice reaction and say okay, and maybe agree, maybe disagree. I guarantee she will feel like shit about her looks at least for a while. Because telling a girl she needs to lose weight, for cosmetic reasons, is admitting to her that you don't like the way she looks. Period. the whole world can think she's ugly, but she expects more from her boyfriend.
just my experience.
I advise be careful. Because if she has a beautiful face like you say, and you're as shallow as it looks, she will find someone better real quick .