This research aims to utilization of food processing by products such as orange peels and apple pomace in some low-calorie bakery products, where this research was to explore the possibility of using of why protein concentration and  some food processing by products (i.e. orange peels and apple pomace) as a fat replacers in biscuits . Impacts on physical, chemical, sensory and nutritional characteristics biscuits samples were prepared by replacing butter up to 75   by whey protein concentrate, orange peels and apple pomace, which were comparable to their full-fat biscuits.  Obtained results showed an observed. decreases in fat content and caloric value in biscuits sample, beside the increase amount in protein content in biscuits prepared with whey protein concentrate and also  increased  in crude fiber in prepared  biscuits sample  orange peels and apple pomace. Sensory characteristics of biscuits prepared with fat replacers showed that color, taste, flavor and overall acceptability of biscuits prepared using different fat replacement (whey protein concentrate) at levels  of 25, 50 and 75% of butter  was increased by the increasing replacement levels, but  overall acceptability  value of biscuits prepared using (orange peels and apple pomace ) was accepted at level of 50% and 25%, respectively.