As I've lot weight, my 'waist' has got higher and higher, assuming it's my narrowest part! Currently it's about 4" below my bra line! i.e. a good 5" above my navel! And way above any natural clothing waist line, even in my 1980's jeans! 
Do you pick a fixed point, like your navel, and measure that? Or should it be your narrowest point even if that changes?
Ditto hips- is that your widest part? That's remained pretty stable!