Im ALMOST over-weight

The waist isn't necessarily your skinniest point. It usually is. But believe it or not there is no actual agreement on this. I guess because human anatomy isn't actually machine like perfect.

In the UK the official measurement is the one the WHO uses. According to the WHO it is half way between your lowest rib and the top of your hip bone. Usually that is two fingers width above your navel as a rough guide.

I'm 5'6 and I currently weigh 8 1/2 stone.

I've never weighed more than 9 stone 4 in my life but I used to weigh around 9 stone before I joined a gym.

Weirdly, I'm still logging the same distance (i.e. 50 miles a week) yet with all the biking/weights & tempo sessions on the tread mixed in, I seem to have shifted 1/2 a stone.

Coincidentally, my pace has become a lot quicker. Now is this because of the weight loss, the fact that I run in more minimal shoes now (Pegasus instead of Nimbus) or simply because I've upped my training?

Who knows.

I am slightly worried though that at this weight (119 pounds) and with a BMI of 19.2, I am putting myself at risk of another stress fracture (had one last year and was around the 9 stone mark then). 

I do eat a varied diet although I am vegetarian but I still consume lots of soya milk/cheese etc. Also, I take calcium/vit D/magnesium supplements religiously.

Also, just to put things in context - I'm a size 8 on top & size 10 bottom. Although sometimes trousers/jeans fit weirdly because I have a tiny waist & muscly legs! 

I can also eat my body weight in pasta

So much to ponder, where do I begin!

D2D, I'm by no means an expert on this but I'm sure I've read before that it's your nutritional intake that determines your risk, not weight per se.

 I think there's some research that puts this down to decreased oestrogen production in women who restrict calories. 

Make sure you're eating enough calories as well as all the supplements. Your energy needs are clearly pretty high if you dropped half a stone without trying.