Inclusion Criteria:  Patients with nasopharyngeal carcinoma confirmed by histopathology Newly diagnosed patients without distant metastasis Age >18 KPS ≥ 70 Nasopharyngeal radiotherapy alone or concurrent chemoradiotherapy was planned to be received, andIMRT was used for radiotherapy The patient's blood counts，the lung, liver and renal functions were tolerant to radiotherapy/chemoradiotherapy（ WBC ≥ 4.0*109/L, NE ≥ 2.0*109/L, PLT 100*109/L and Hb≥ 10g/L. AST and ALT ≤ 2.5 *the upper limit（UL） ,TBIL≤1.2*the UL, CRE≤1.2* the UL, and ALP≤5* the UL）. And the ECG should be normal Good nutritional status,BMI:18~23Kg/ m2, PG-SGA ≤1,NRS 2002<3score No other previous neoplastic diseases, except for cured cervical carcinoma in situ skin basal carcinoma No serious gastrointestinal diseases (moderate and severe duodenal and gastric ulcer, ulcerative colitis, Crohn's disease, etc.) No AIDS and no diabetes Clear mind, no communication barriers, able to answer questions Voluntarily participate and sign the informed consent in person.  Exclusion Criteria:  Patients with gastrointestinal dysfunction, intestinal obstruction, pyloric obstruction, Acute gastrointestinal bleeding Patients who are allergic to nutritional therapy or have severe allergic constitution Uncontrolled systemic diseases, such as severe liver disease (such as cirrhosis), kidney disease, respiratory diseases and so on. Women who are pregnant or breastfeeding or no contraception and women with positive pregnancy test before receiving treatment Special dietary requirements: such as no having a certain food or a vegetarian.