Background/AimThe present study quantified the changes in the dietary and nutritional intake after gastrectomy between elderly and non-elderly patients.Patients and MethodsThis prospective observational study enrolled patients who underwent curative gastrectomy for gastric cancer.ResultsTwenty-three patients ≥ 75 years old were classified into the elderly group, and 127 patients < 75 years old were classified into the non-elderly group. The respective median % dietary intake losses at 1 and 3 months postoperatively were −12.4% and −5.3% in the elderly group and −8.3% and −2.8% in the non-elderly group (p= 0.075 and 0.080). On comparing the intake loss of three major nutrients, the respective median % lipid intake losses at 1 and 3 months postoperatively were −13.5% and −5.8% in the elderly group and −7.3% and 0% in the non-elderly group (p= 0.029 and 0.045).ConclusionOur results suggested that elderly patients experienced more serious lipid intake loss after gastrectomy than non-elderly patients.