Which is healthier? Lower calorie and fat?

If you're trying to lose way I'd stay clear of the white bread. Carbs (specially processed ones) turn into fat. Actually I remember reading somewhere that people who eat one slice of withe bread a day and stopped lost 10 to 15 pounds in a year. Besides carbs make you gain weight like crazy. If you wanna do the sandwich try to use whole grain but if you really wanna lose weight you should eliminate all kinds of bread from your diet. Try healthier carbs like beans, chickpeas, potatoes and fruit (banana's are great for energy).