Thank you for the input, guys.
*ltzjstjeff*, I have created my own RDI already; like I said, I've set it to 1450. That isn't the issue though. It's the daily variations that are the problem.
*jad59*, yes, I do try to eat more on very active days but then I'm not talking about being just a little more active. Quite often, after doing an hour's run in the morning, I also do several hours of really heavy physical labour, as we're renovating a house just now. (By "heavy labour", I mean like shifting 73 concrete slabs, building a large sandstone rockery on my own, or painting and decorating high ceilings and cornices for 7 hours on end, etc.) While I might appear to lose more pounds if I didn't increase my calories on those days (especially the protein), actually it would probably be muscle loss, rather than just fat. And, as we all know, the muscle helps burn the fat and keep the weight off long term.
I guess I'll have to go with your approach *thinner 120* and just ignore the fact that it looks like I'm overeating on certain days. I suppose it's just one of the limitations of FS daily logging but it's definitely more than balanced out by the positives. And as long as I know what I'm doing, it doesn't really matter how it looks.
Still hate the red though
So any further suggestions or solutions would be much appreciated!