Why do peptic ulcers lead to weight loss? does it happen even if one eats?

May hurt to eat: The main reason is that the upper abdominal nausea, vomiting & pain caused by ulcers impair appetite. Interestingly, many ulcer patients report that their symptoms improve with certain low acid foods such as bananas, peaches, pears and worsen with spicy foods. There could be some weight loss if severe ulcers cause scarring & swelling resulting in mild obstruction & poorer absorption of nutrients