I’m the size of a typical American pre-teen (or adult male runner)
I thought this might happen. For at least a moment in time, as a 36-year-old, 6’0” tall man, I’ve fallen below 150 pounds. This is despite filling myself to exhaustion with rich, fatty foods like avocado and nuts and salmon and eggs and coconut milk, along with daily protein-and-carb-and-nutrient-dense 40-ounce shakes.
If I remember correctly, my half-grown freshman in high school self was about 160 pounds. When lifting weights a lot post-college I got up to a lean 195 pounds. As recently as 2010, when running nearly as much as I am now, I was around 165 pounds. Many non-running friends assume that I’m just “running too much” but, by competitive runner standards, my 40-65 mile weeks (only occasionally spiking higher) are equivalent to the off-weeks. Those guys and gals consistently log 100+ weekly miles and some elite runners are known to do almost twice that.
The upside is that I can probably fit into my Bar Mitzvah suit. And I now look extra svelte in my brand-new racing vest. Sagan and Alison encouraged many, many photo shoot poses but I have to say, for better or worse, this is the one we like best:
Kind of Like Fun 
The vest rocks!
The vest (bra) is, uh, quite becoming. HOWEVER… Mom says, “Eat more!” You LOOK great, but you need a few “reserve” pounds. Love you… Mom