I worked at a subway a million years ago. Certain things have changed since then. Some others I'd guess are still the same, but back in ye olden days:
- we cut the tomatoes, onions and green peppers in the back. This was exactly the stuff you'd get from a grocery wholesaler and by extension, buy yourself at the market.
- the lettuce came pre-cut in vacuum sealed bags. I don't think it had any preservatives.
- the pickles, olives and hot peppers came in pretty standard food-servicey bulk packages
- the cukes were introduced long after the time I worked there
- the brown bread is (was) only 33% whole wheat. The brown colour is from raisin syrup.
- I don't know anything about the current deluxified breads, though I think that there are only still the two basic breads, and the toppings are simply shaken on top before baking.
- back then, the cheese was processed. However, I think at least some of the current cheese choices are "real", based on how the slices crumble and how you can see the blade marks on the cheese.
- back then, there was mayo and "mayonnaise-style dressing", which was significantly lower in fat. The dressing was what was mixed into the tuna and seafood mixes. I' m not sure what the deal is these days.
- incidentally, the seafood & crab was pollock with, if memory serves, a bit of snow crab.
- what looks like deli meat (roast beef, turkey, pepperoni) is roughly equivalent to the stuff you can buy at Safeway, for better or for worse.
- IMO Subway can be okay for you, as much as Mcdicks can be okay for you.
I think it's easier to make shitty menu choices at McDs though (want fries with that?). It also depends on what sorts of evils you prefer -- fat can be fairly easy to avoid at Subway, but you're usually trading more heavily processed foods.
All told it's fast food. You should never expect fast food to be healthly, and you should never really expect to be able to go out and eat and be healthy.
BTW, I absolutely believe that McDs uses 100% beef. You probably don't want to believe exactly how or what makes up that 100% though
Interested? check this out... http://www.nytimes.com/2009/10/04/health/04meat.html