Cut back on that sandwich's calories without reducing taste and pleasure.
A ham sandwich can easily have 450 or more calories. Here's a way to eliminate a couple of hundred without even trying.
Bread: Switch from white to whole grain. 50 to 100 saved
Mayo: Replace it with spicy mustard and some pickles. 100 or more. Lettuce: Add it. Nearly nothing added. Eat slowly, take small bites and chew them thoroughly. You get full and you may not finish the sandwich. Another 50 to 100 saved.