I followed the same path as Sirs Edward and William - low-mid 100s all the way through high school, and at my last weighing a month or two ago I pegged 230 lbs. My wife says "remember muscle weighs more than fat" and I am hiding a lot of muscle under my fat (or so I say/hope
). Oddly enough, it's all been mid-section gain, resulting from being an active teenager and then sitting behind a desk or steering wheel 10+ hours a day for the last decade. I can still fit into my plate arms and legs from the late 90s, but a plate cuirass would be questionable - on the bright side, a well-made cuirass in most styles will have some range of at least 3-4" in girth by reducing or increasing the amount that the sides overlap.
Buying properly fitted armor is more important when you're moving in it for combat. I made the mistake of wearing a harness to VARF which didn't fit quite right. The greaves were too small, so I left them off and wore the cuisse and demi-greaves below the knees. Well, after maybe an hour (or less) of *just* walking around the faire, I armored down because my leg was burning. I put on my soft kit, which didn't involve removing the pants or boots. Got home that evening - I had a small chunk of flesh missing from my lower leg, right where the demi-greave ate through my skin from rubbing up and down every step. That was 5 months ago, and I still have the scar from that.
I can't overstate the importance of proper fitment and proper padding.
Go with a closer fitted gambeson than looser; if the base garments don't fit right, the whole thing will be "off". Plates will move easier and more naturally the closer it is fitted to your body, since it moves more naturally and won't stress the articulation as much.