Hey Baffled -- so much of this weight loss business is a total mystery.
I don't have a great answer for you, but if you're eating correctly and working out with weights and cardio, you're doing exactly what you should be doing. The five pound loss most likely is fat pounds because I know you're lifting weights (pretty intensively, I recall
) It's unlikely that you lost muscle with your exercise routine.
So if it's not muscle loss, it has to be fat (or water, but that seems unlikely). Why isn't it showing up on your tape measure? I can think of two possibilities -- one, measurement error or two, you're losing fat from places you don't measure.
It's hard to consistently measure in the same places and you can get tremendous variance just by moving a tape measure up or down an inch. Plus my waist measurement can change by an inch or two depending on my salt and carb intake.
Or it could be that your body is changing and losing fat from weird places, like your neck or ankles or someplace you don't typically measure. I lost a lot of weight in my fingers and wrists!
How are your clothes fitting? Have you noticed a change corresponding with the weight loss? That might be a better indication than measurements.
I know it's puzzling, but it really sounds like you're on the right track!