The thing about Meru-chan, since someone brought up The Feelings We All Must Deal With, is that she's not a stereotype and she's certainly not played for comic relief; her weight isn't really a joke when it comes up. And I thought the way the series ended for her was cute and a lot healthier than this one here.
This feels fetishizing, but sweet exercise despite being better kinda does too (it definitely falls into that sort of patronizing trap you see where a moderately-sized girl is portrayed as a symbolic progressive heroine for the industry to rally behind because she's somehow "plus-sized"). But yeah, it's certainly better because, again, it doesn't really feel like the joke is her weight -- more her neuroses about it and the story is about how she and her girlfriend work through it, so it's much cuter. (also I like the bit with the jump-rope bondage hehe)
It's a real sticking point for me because my girlfriend is always concerned about her weight and how it makes her look, so when I see something like this it really pisses me off because argh it's not helping. And the relationship dynamic is just, well, like y'all been saying.