For dating, your physical weight matters a lot. But arranging marriages is about focusing on what matters in the long run. Most women get fatter with age, so men shouldn't worry too much about this at marriage time.
The major difference is that even with all the bad nutrition advice out there "remain thin" is still possible and easy. Men who do so can end up skinny fat which is a fail case for men but women who *just stay thin* have succeeded. If you're a single fat woman, you're a failure