Flying Waitress,
Size 18 is not actually that large, especially if you are also reasonably tall.
I agree with you about the logistics of working in small spaces, but I disagree about your perception of health and size. Just because you may be bigger, does not necessarliy mean you are unfit and unhealthy. You may find that many larger people exercise regularly and are quite fit.
Also, a big contributor to heart disease in constant dieting. And *and* smoking. Which people of all shapes and sizes partake in. Maybe you should be checking out who's having a quick fag before their shift and steer clear of them...