My BMI shows 'normal' and to most people I look 'fit', although I personally could get away with 30 less pounds (max) due to cellulite and the fact that I distribute my weight well enough that it is not overly apparent when I am lugging around a few extra pounds.
That being said, the joint pain is from a short leg, flat feet and a fused hip/ vertebrae causing me to overpronate. It makes me roll too much weight, the wrong way, on that one big toe knuckle.
I call it a 'bunion', but instead of the pain residing in the bump on the outer part of the foot, the pain is inside the joint. It doesn't help that I am taking Taekwondo and we do a lot of rotating on the ball of the foot.