Just to say good luck Mikie, my husband weighs around 15 1/2 stone and runs a few times a week to keep fit, did his first 10K race in Jan in 51 mins. Still has a belly but then he does like the odd beer.
However, his sister says that even when he was incredibly fit having completed a year long attachment to the US Army, and weighed 12 1/2 stone, he still had a bit of a belly. Most of his family seem to lay down fat in that area, his sister, brother and mum are the same. Is there a similar tendency in your family? If so maybe you have to contend with genetics as well as food/drink intake and will have to adapt eating and exercise to take account of it?