Abstract: ObjectiveTo assess the level of total energy expenditure (TEE) and its association with oxidative stress in patients with type 2 diabetes.MethodsPatients aged 30-70 years with type 2 diabetes mellitus were selected from a general hospital in Guangzhou as the subjects. Their information about 24-hour physical activities were collected to calculate the TEE using the factorial calculation. ELISA was used to detect the concentrations of 8-OHdG and 8-isoPGF2α in urine to evaluate the level of oxidative stress. Pearson correlation coefficient and multiple linear regression were used to analyze the correlation between the oxidative stress and TEE.ResultsA total of 222 patients were finally involved in this study. Of them, 47.7% (106/222) were females 48.6%(103/222) were aged 30-49 years, and 59.0%（131/222）were from Guangdong Province. Rest and very-low activity were accounted for 86.6% and 83.4% of the total time in males and females, respectively. Compared with females, males spent less time on light activity(P<0.01）， while more time on sitting（P<0.01）. TEEs were 160.4 kJ/（kg?d） for males and 153.3 kJ/（kg?d） for females, and higher in each age group than the corresponding RNIs at heavy physical activity level. Pearson correlation analysis showed that the concentrations of 8-OHdG and 8-iso-PGF2α were positively correlated with TEE (P<0.05 and P<0.01, respectively). Multiple linear regression showed that TEE was an influencing factor for the concentration of 8-OHdG and 8-iso-PGF2α (both P <0.01).ConclusionTEEs of patients with type 2 diabete mellitus and heavy physical activity were higher than RNI, and may affect the concentrations of 8-OHdG and 8-iso-PGF2α in urine and increase the level of oxidative stress.