Preheat oven to 375 degrees F (190 degrees C). Lightly grease a 9x5 inch loaf pan.
In a large bowl, combine melted butter and honey. Whisk in yogurt, egg and lemon juice.
In a separate bowl, sift together all-purpose flour, whole wheat flour, baking soda, nutmeg and cinnamon. Fold this mixture into the yogurt mixture, stirring just enough to blend. Pour batter into prepared loaf pan.
Bake in preheated oven until top of loaf springs back when touched and a toothpick inserted into center of the loaf comes out clean, about 50 minutes.