Waldorf Salad

1 teaspoon lemon juice
2 1/2 cups diced apples
1 cup thin celery strips, about 1-inch long
1/2 cup broken walnuts
1 tablespoon granulated sugar
Dash of salt
1/2 cup low-fat yogurt
2 tablespoons mayonnaise
Crisp lettuce leaves

Drizzle lemon juice over diced apples; toss well. Mix in celery and walnuts. Blend together sugar, salt, low-fat yogurt and mayonnaise. Fold into apple mixture; chill.

Serve on lettuce leaves.