Feeding during dialysis—risks and uncertainties

Allowing dialysis patients to eat during the treatment is controversial. It is, therefore, no surprise that practices and policies with respect to intradialytic food consumption vary considerably from unit to unit and from country to country. Those who defend the position of feeding during dialysis reason that intradialytic meals offer a supervised and effective therapy for protein-energy wasting. Those who take the opposite view argue that intradialytic food intake should be avoided for the following three reasons. First, interventional studies show that eating during dialysis causes a clinically significant reduction in systemic blood pressure during the postprandial period and elevates the risk of symptomatic intradialytic hypotension; the latter is associated with increased mortality risk. Second, clinical studies have shown that eating during dialysis interferes with the adequacy of the delivered dialysis, whereas eating 2-3 h before the dialysis session has no impact on the efficiency of the subsequent dialysis treatment. And third, randomized studies show that eating during dialysis focus on the positive outcomes but do not adequately balance this potential benefit against the risk of intradialytic hemodynamic instability and poor quality of delivered dialysis. Even after half a century of providing long-term dialysis, definitive randomized trials that balance risks and benefits of eating during dialysis are missing. These knowledge gaps require randomized trials. Since there is a real possibility of harm with eating during dialysis, we caution that instead of encouraging the widespread use of intradialytic meals, practices and policies should focus on adequate nutrient intake during the interdialytic interval.