Eating on Dialysis Treatment: A Closer Look

Nutrition status is a known factor impacting the health and well-being of patients on in-center hemodialysis (HD), with albumin being one of the strongest predictors of mortality in this patient population. Due to the increased nutrient demands that HD requires, patients often fall short of recommended protein and energy intakes, with even lower nutrient intakes reported on treatment days.

Given the amount of time that patients spend on in-center HD, it’s no surprise that timing conflicts between meals and treatment commonly arise. While it’s conceivable that timing intakes during HD may provide an advantage in protecting against the catabolic effects of treatment and improving nutrition status, eating during HD remains controversial.

Changing Perspectives

Even though eating during treatment is considered routine in many countries, the practice varies significantly amongst clinics around the world. Practices regarding intradialytic feeding in the United States have traditionally been more restrictive, although a shift toward encouraging oral nutrition supplements has been occurring in recent years. Given these inconsistencies and recent research interest, the International Society of Renal Nutrition and Metabolism issued a 2018 consensus statement regarding eating on treatment, weighing many of the commonly cited concerns against benefits observed in studies.

Among potential risks, the consensus statement considered the following:

• Post-prandial hypotension
• Gastrointestinal (GI) symptoms
• Reduced treatment efficiency
• Risk of choking
• Increased staff burden
• Food safety

Conversely, proponents of eating during treatment point to many possible benefits, including:

• Reduced mortality
• Improved nutrition status
• Better treatment adherence and quality of life
• Provision of more appropriate food choices
• Educational opportunities

Despite concern over these issues, particularly post-prandial hypotension and GI symptoms, a 2014 survey of international dialysis professionals indicated that many of the anticipated negative effects of eating on treatment may not be frequently observed in practice. Ultimately, the consensus statement concluded that while more randomized controlled trials were needed, studies suggest that providing meals or nutritional supplements remains an effective approach for improving nutritional status in hemodynamically stable patients without a history of intolerance.

Considering High-Protein Meals

Of additional interest, some recent studies have gone beyond supplements and examined the impact of providing high-protein meals during treatment.

A randomized control trial looked at the effect on albumin and phosphorus levels of providing high-protein meals along with lanthanum carbonate as compared with low-protein, low-phosphorus meals during HD among 110 hypoalbuminemic patients. Twenty-four high-protein meals were given to patients over 24 HD sessions, each providing 50-55 g protein, 850 calories and 400-450 mg phosphorus. Low-protein meals given over the same timeframe provided < 1 g protein, < 50 calories and < 20mg phosphorus. After the 8-week intervention, 27% of patients studied in the high-protein group achieved at least a 0.2 g/dL increase in albumin while also maintaining serum phosphorus within target range compared with 12% meeting these parameters in the low-protein group (p = 0.45). No significant adverse events were reported in either study group. As noted by the study authors, even small increases in albumin are associated with improved outcomes in HD patients. They conclude these findings demonstrate that high-protein meals in combination with lanthanum carbonate are safe and can increase albumin while maintaining desirable phosphorus levels.

More recently, a pilot study in 18 HD patients divided into two groups—intervention and control—looked at the effects of high-protein meals during HD on blood pressure outcomes. Patients in the intervention group received meals of about 30 g protein and one-third the recommended intakes for phosphorus, potassium, sodium and fluid while on HD for 25 consecutive treatments. Patients in the control group were visited during each treatment by a study volunteer and given a small treat of hard candies but no meal. Symptomatic hypotensive events occurred during both the prestudy and during study periods for members of both the intervention and control groups. However, change in frequency of symptomatic hypotensive events did not differ significantly between the intervention and control groups, suggesting that providing meals during HD did not affect the frequency of symptomatic hypotension events.

With regard to GI concerns, another recent study found no difference in GI symptoms between patients who chose to eat during treatment and those who did not. While average nutrient intakes were generally smaller in this study, more indigestion was reported among patients eating larger amounts of dietary fat and fiber. In light of this, dietitians may consider macronutrient composition when working with patients to identify meals and snack options that may be better tolerated during treatment.

Nutrition Interventions

Given the possible benefits of eating during treatment suggested in recent research, dietitians may consider practical ways to encourage significant intakes during treatment while also minimizing patient risk or possible logistical issues. Some strategies may include the following:

• Provide ongoing patient and teammate education regarding best practices for eating on treatment.
• Give clear safety guidelines to eat slowly, chew thoroughly and only eat when sitting upright.
• Instruct patients to only bring food items that meet the practical needs of the facility and team, such as foods not requiring refrigeration, heating or other significant assistance from staff to consume. Foods that are messy or have strong odors should also be discouraged.
• Use eating on treatment as an educational opportunity to discuss fluid intake and promote renal-friendly foods that are protein-rich and low in phosphorus, potassium and sodium.
• Counsel patients individually on macronutrient content of the foods they bring to dialysis, particularly if GI symptoms have been previously reported.
• Request that patients who take phosphate binders to bring them and take them as ordered by their doctor.

It is important that dietitians record a history of each patient that includes the presence or absence of previous intolerance to eating on treatment and the details surrounding each occurrence. While eating on HD will not be appropriate for every patient, using the tips above could help lead to reasonable adjustments to mitigate barriers in some instances. Lastly, working with the interdisciplinary team at the clinic level to evaluate both current facility methods and best practice goals might be the first step in promoting this valuable nutrition intervention.