I'm a size 12/14, and 5'8". I don't weigh myself, but my waist is about 33" or so. I have child-bearing hips and a big bust so certain clothes might technically fit (comfortable, no pulling of fabric, etc), but my size 8 pre-teen daughter looks much nicer in them.
I've also found that the cut of the clothing makes a huge difference in fit. I have jeans with a low rise and a pair that are high-waisted -- the low-rise jeans aren't as forgiving of my mum-tum because they finish right on my hips. High-waisted jeans in the same size tend to be too loose.