The energy and nutrition states are closely associated with CKD patients complications and outcomes.To reach the energy balance target, we need the accurate resting energy expenditure level of patients. Traditional equations are not applicable to CKD patients,so we aim to develop and validate a equation for estimating resting energy expenditure in CKD patients.

Inclusion Criteria:

• CKD 3-5 stages
• Age:18-80 years old

Exclusion Criteria:

• Dialysis and kidney transplantation;
• Acute complications to hospitalization
• 1 month prior to the study;
• Acute or chronic infections, cancer and other wasting diseases in the past year;
• Thyroid dysfunction;
• Acute onset of podagra; Musculoskeletal diseases;
• Respiratory diseases (asthma, pleural effusion, pneumothorax, COPD);
• History of hormonal drugs use;
• During pregnancy or lactation

chronic kidney disease 3-5 stages