Nurses - an observation

I might take some heat about this but I made an observation the other night at the local hospital.

Nurses and Aides in hospitals have a very demanding job. They deal with patients day in and day out from giving them baths and showers to putting them on bed pans. They take patients for walks and at times transport them from place to place. They change the beds, give meds, serve food and do a lot of physical things with them. The list of things they do goes on and on.

So then answer me this... Why is it that a large majority of the Nurse and Aide population in a hospital are over weight?

Wouldn't you think that with the amount of walking and physical activity that they go through day after day that they would be fit and trim? What is it that causes a large percentage to be over weight?

My wife works in the hospital and I know the things that they do on their floor. I know they are on their feet pretty much all shift and in some cases they pull 16 hour shifts and just keep going. With so much physical activity you would think that they would not be large women and men. For some reason though they are. Is it the hospital food they eat? I know the ones that work with my wife order out or bring their own so it can't be that. Even so the physical activity would certainly burn the calories that they take in. There are those that are lazy and do sit around a lot but the majority are on their feet and moving all the time. So what is it?

I would love to have some input on this.