Foods supplemented with functional fiber are an effective means for prevention of diseases like obesity, cardiovascular diseases, and diabetes mellitus. The objective of this study was to estimate the dietary fiber content in artichoke stems by-product powder (ASP) and shrimp by-product powder (SBP) and evaluate the protective effect of diet supplemented with their by-products as natural dietary fiber on weight gain, the blood picture, serum biochemical parameters and liver enzymes activities in obese rats. The results revealed that the crude fiber content was 22.68% in the ASP and 13.65% in SBP. Total dietary fiber fractions were composed of 18.69 and 0.42% soluble dietary fiber, 25.01 and 58.57% insoluble dietary fiber in defatted ASP and SBP, respectively. They also presented high amounts of inulin (18.2 g/100 g artichoke stem) and chitin (58.15 g/100 g shrimp shell). Biological impacts were done on the control group (CG) and compared with obese rat groups which were classified into seven groups; positive group (PC) and groups fed on diet supplemented with ASP and SBP at a level of 5 and 10%, inulin at dose 7.7 %, and chitosan at dose 2.6 %, for 8 weeks. The results showed significant improvement and ameliorated reduction in final body weight, body weights gain (%) and feed efficiency ratio (FER) in all the treated groups compared with the PC. Administration of 10% ASP or SBP significantly decreased body weight by 37.66 and 35.61%, respectively as compared to the high fat diet (HFD) group, while the highest reduction in body weight gain and lower FER were obtained in groups fed on chitosan. Feeding obese rats on diet containing ASP and SBP led to a reduction in the total cholesterol, triglycerides, and low-density lipoprotein cholesterol concentration, decreased in blood glucose level and improved serum liver enzymes activity and antioxidant enzyme activity as compared to the positive group. ASP as a source of inulin and SBP as a source of chitin can be used in the nutraceutical formulation of functional food products and a good source of natural dietary fiber to enhance the nutritional quality for prevention of diseases like obesity, and its associated health risks.