Energy balance in advanced chronic kidney disease and end-stage renal disease.

Energy intake, resting energy expenditure, and energy expended for physical activity (EEPA) are components of energy balance that may be disrupted by a number of disorders and clinical conditions commonly present in advanced chronic kidney disease (CKD) and end-stage renal disease (ESRD). Energy intake of patients with CKD has been consistently lower than the recommended intake in multiple reports. On the other hand, while reduced energy intake due to anorexia may be applicable for ESRD patients with overt protein-energy wasting, it is potentially unrealistic for overweight or obese subjects who are able to maintain their body weight. Studies on resting energy expenditure have provided mixed results, most likely as a consequence of differences in the population characteristics, clinical conditions, and stage of the disease. Finally, although there is lack of specific studies on EEPA, there is evidence that ESRD patients, particularly those undergoing hemodialysis are in general less active than sedentary healthy individuals. These observations may raise questions regarding the accuracy of dietary reports and the uncertainties related to the energy requirements, optimal dietary energy intake, and recommendations for physical activity in these patients.