Autumn Fruit Salad

2 Granny Smith apples
Zest of 1 lime
1 can (11 ounces) mandarin orange segments, drained
1 cup halved seedless red grapes
1 1/2 cups miniature marshmallows
1 carton (8 ounces) vanilla low-fat yogurt
2 T. chopped nuts (optional)

Peel and cut up apples. Combine yogurt with lime zest in a large bowl and mix in apples, mandarin oranges and grapes. Add marshmallows and mix gently. Sprinkle nuts over top. Refrigerate until ready to serve. Yield: 12 servings