Table 1.

Limiting food versus allowing liberal nutrition in dialysis patients.

	Rationale	Pros	Cons	Controversial and Unclear Issues
Salt (and water)	Limits weight gain, improves hypertension control and dialysis tolerance.	Low sodium intake is feasible and associated with better blood pressure control and dialysis management.	Limiting salt may reduce palatability and induce anorexia; it may not be an option for patients living in retirement homes, or receiving cooked meals at home.	How to manage Na and water restriction (if any) in patients with residual kidney function.
Potassium	Limits the risks of hyperkalemia.	Potassium is derived from diet, and its reduction in the diet can reduce the risk of hyperkalemia.	K restriction is commonly interpreted as reduced consumption of fruit and vegetables, which are associated with better cardiovascular outcomes.	The missing factor is potassium absorption, which may be enhanced in the case of slow intestinal transit, enhanced by a diet poor in fibers and use of potassium binders.
Phosphate	Counterbalances CKD-related metabolic bone disease.	Phosphate levels are associated with vascular calcifications; a high phosphate level is cardiotoxic and is a stimulus for PTH secretion.	Phosphate content is higher in protein-rich food; therefore, too strict a reduction can be incompatible with high protein content.	The issue of phosphate added to food is only partially known. The role of additives may be more important than previously appreciated.
Lipids	Counterbalances cardiovascular risk and accelerated atherosclerosis in dialysis patients.	Dyslipidemia is a common finding in dialysis patients; nutritional interventions should always come first.	Lipids are important sources of energy. Restriction should be balanced against the indication for high energy intake.	The role for statins in dialysis patients is controversial; physical activity may be an important non pharmacologic aid to control dyslipidemia.
Carbo-hydrates	Counterbalances carbohydrate intolerance of uremic patients.	In several dialysis settings, more than half of the patients are diabetic; carbohydrate intolerance is commonly associated with worse outcomes.	Carbohydrates are important sources of energy. Restriction should be balanced against the indication for high energy intake in dialysis patients.	Physical activity may be an important non pharmacologic aid to improve the overall metabolic balance.

Legend: CKD: chronic kidney disease; PTH parathyroid hormone.