So if you compare eating cheaply at a Thai restaurant or eating at Food Courts in Thailand how does that compare if you eat out at places like Chillis, Big Bowl, and other Lettuce Entertain you chain restaurants?

depending on your choice - you can get a 'healthy selection'. there are many veggie dishes, chicken, minced pork type dishes which are healthy and of course the red chilly.

Eating at Chillis (US) for example is greasy...food. I think you can determine the heath factor by observing the waist-line at any specific restaurant.

It really depends on the court. In recent years I think the quality of many food courts has improved vastly. Fifteen years ago there was very little available but quite cheap meals which were barely edible. Now some of them offer food which is quite enjoyable. Some even offer a reasonable copy of Western food. Not restaurant standard, but far, far better than street food. Clean kitchens and staff, washing facilities, good environment (except for the TV sets).

Of course, they're not all like this. The bigger the store, the better the food court. Beware of the sugar in the Mayonnaise and salad cream. I've never seen a food court get this right, but they are for Thais, and Thais like sugar in everything.