Scale won't budge

My opinion (wich you are more than welcome to ignore): Your clothes are still fitting so I assume you did not gain any real fat. It might be more muscle as mentioned above or it might be something to do with glycogen stores or water retention changing since you started running. You don't seem unhappy with the way you look, just that number, so try to forget about it and be happy that you are now this awesome runner

That's pretty much what I was going to say. You're going to pick up a few pounds for the recovery water and glycogen stores your muscles need. I bet if you stopped for a week or two those pounds would disappear. I wouldn't worry about the number on a scale. If you were 300 lbs and still had a rocking body would you care? Na. I doubt it. Measurements supercede weight. Weight is only one tool to measure fitness not the end-all.

I ALWAYS gain about 5 lbs when I first start running, but then lose it and then some - I think it is a combo of muscle development in my legs, and my body wanting to hold onto fluids.

Muscle does NOT weigh more than fat. A pound is a pound, just different density.

While true this is just nit-picky and not particularly relevant.

I would still encourage you to look into your reasons for wanting to lose those 5lbs and if it really needs to be done.

How is this not relevant? Lol. A pound is a pound is a pound.

OP lost 100 lb and kept it off 10 years! WAY. TO. GO!

I can't touch that, but I have kept my weight within a 5 lb range for 30 years (not counting pregnancy). I totally understand the 5 lb rule mentality. When I'm up 5, I lose it. Otherwise it becomes "the new normal" and my range will creep up. Also, I do think that last 5 is a totally different game than a huge loss--not harder by any means, but different. It's all about caloric deficit (that part is the same), but the deficit is so small to spare muscle that it requires precision, patience, and scale weight averaging over a week (or more!) to really see what's going on. I've never lost 5 lb in less than 3 months.

Is running the only thing that changed in that year and a half that the scale move up? Have you checked your BF%? 5lb rule notwithstanding, I would love, love, love to put on 5 lb lean body mass, but I haven't bellied up to the considerable effort that would take. If you have gained LBM, I would definitely try to keep that!

So the food scale is for all solids, not just meat Even the cereal , you could set your cereal bowl on the scale, Tare it to zero, add the cereal - not the half cup measurement provided as a serving size, but the XXg listed beside the half cup. This can be really eye opening as measurements do not always match the weight. Anything that isn't a freely pouring liquid can be weighed. Do this to whichever extent you can without being turned off from the process. A digital scale with g and oz measurements, as well as a Tare button can be had for ten bucks. You definitely shouldn't need to spend more than 25

These may have already been posted (possibly even by me) but I'll just add them again. They have tips on recording accurately using a food scale:

http://www.myfitnesspal.com/topics/show/1296011-calorie-counting-101

http://www.myfitnesspal.com/topics/show/1234699-logging-accurately-step-by-step-guide

Over the past year and a half, when you were starting to run and were gaining those pounds, were you eating at a deficit, at maintenance or a surplus? Any weight lifting during that time? Running is a weight-bearing exercise, so you can sometimes see an increase in bone density, but it's dependent on a lot of variables (and wouldn't happen if you were eating at a deficit).