Abstract : Background: Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic fatty pancreatic disease (NAFPD) are expected to increase because of the rising prevalence of central obesity. Aim: to study weight reduction effects on metabolic, anthropometric, and ultrasound parameters in non-diabetic, overweight, and obese people with NAFLD and NAFPD. Subjects and methods: 133 adults aged 35-65 who were obese or overweight and had no diabetes participated in this study for six months. Participants underwent an individualized, intensive lifestyle program that included dietary changes. The diet recommendation was a low-fat hypocaloric meal. All subjects underwent ultrasound (US) examinations before the program, at 3rd month as well as at 6 months. We assessed the effects of weight loss on NAFPD (at baseline, 3 months, and 6 months) by linear mixed components. Result: Triglycerides and transaminases, two laboratory parameters, were significantly reduced by the ending of the study. The ultrasound outcomes revealed that in non-diabetic people who are overweight or obese, losing weight significantly lowers NAFLD while leaving NAFPD unaffected. No association was found between NAFPD and anthropometric parameters, blood pressure assessments, or blood indicators at rho > 0.4. Conclusion: weight reduction leads to a substantial drop in NAFLD in overweight and obese non-diabetics. Losing weight, on the other hand, seems not to affect the NAFPD.