Weight is a proxy because nobody is out getting dexa body scans weekly to see how things are going. Nobody cares if you lose 10lbs of water weight and that isn't what we are talking about. But if you weigh average 115lbs on your morning weigh in and 4 months later you are averaging 105 for the month, we are talking about significant changes
We might have better treatments but is there any evidence that we are catching it any quicker? Or are we all pretty much stuck waiting til someone reaches rock bottom? Maybe we don't hear about the early detection cases, but the list of elite HS athletes who struggle in college with ED issues seems endless.
As far as looking like a runner, it means exactly what it sounds like. If you go look at a pro race 9/10 have the same frame and look. Occasionally you get some exception. Same thing is said in tons of other sports.
In the end the problem will be that lighter is faster up until you get too light. And for a ton of people to get close to the too light category requires actions that border on ED.
It is interesting that there are a few woman who do seem to go a career being skinny without an ED. Jordan Hassay is pushing 30 and having been talking about when she would break down since HS.
If you were a coach, would you be able to tell the difference between her and say Seidel or Allie? Especially in HS.