Have you heard the phrase "Strong is the New Skinny"? I think, as always, there's an element of truth, but not the whole truth there. Certainly looking back at old "Top of the Pops" from decades ago, our boy bands were a great deal less buff than the more recent ones. Many girls are working hard to improve their glute shape and their arms, rather than just wanting to be as thin as possible. It is probably a more healthy society where having some shape is considered desirable. The worry is that some may just see lifting heavy weights as a way of justifying what is in fact an unhealthy, overfat body.
Being strong is good. Being the strongest is just a competitive thing. Being slim is good. Being obsessed at being the thinnest is a really bad idea. Let's concentrate on all-round fitness, not just one aspect of it. That means healthy heart and lungs, a strong core and muscles, flexible joints and great balance, as well as a body weight that is healthy for the individual.