I can relay what I remember my ET telling me... start off with iceburg lettuce. It's crunchier and easier to chew, not as string as say, fresh spinach. Yes, go ahead and eat the lettuce on subs. You will probably have better luck eating lettuce with a meal at first, rather than before your meal. A lot of folks have absolutely no problem with lettuce or veggies, or fruits. You may not either but introduce them slowly to be sure. Go ahead and experiment --- that is the only way you will ever know. Chew, Chew, Chew and drink lots of liquids...