Is my diet a healthy one, your opinion please.

Every morning I have a hardboiled egg on 2 pieces of whole wheat bread with lettuce. I go for a 3 mile walk with my dog. Afternoon, I have 2 thin slices of turkey with 1 slice of swiss cheese along with lettuce, tomato and a kosher pickle. Dinner is a salad with lettuce, tomato, onions, green pepper and cucumber with several pieces of cut up baked chicken breast. I am losing weight, but should I be eating something else, or is this healthy enough?