Currently Available Handouts for Low Phosphorus Diets in Chronic Kidney Disease Continue to Restrict Plant Proteins and Minimally Processed Dairy Products

The 2020 Kidney Disease Outcome Quality Initiative guidelines recommend adjusting phosphorus intake to achieve and maintain normal serum phosphorus levels for adults living with chronic kidney disease. These guidelines also recommend considering the dietary source of phosphorus as different sources have different bioavailability; however, phosphorus food lists are not provided. Therefore, the aim of this study is to investigate the current teaching materials in Canada regarding low phosphorus diet.

Using a geographical approach, websites from each province and territories' government, health, and renal programs (where applicable) were reviewed for resources on dietary phosphorus restriction in chronic kidney disease. All publicly available handouts/booklets/printable webpages were obtained and reviewed for recommendations on how to implement a low phosphorus diet.

Sixty-one resources in total met inclusion criteria (52 handouts from health agencies in 6 provinces and 9 handouts from the Kidney Foundation of Canada). Items with minimal nutrition value, such as cola, beer and cocoa, chocolate, and baking powder, were the most commonly restricted with 84% (51/61) resources making this recommendation. Plant proteins and minimally processed dairy were restricted in 80% (49/61) of resources. Processed animal meat was recommended to be restricted in 70% (43/61) of resources and whole grains in 65% (40/61). Sixty-three percent of the handouts (39/61) discuss avoiding phosphorus additives.

Many resources restrict items with minimal nutrition value to lower phosphorus intake; however, plant foods, including plant proteins and whole grains, continue to be restricted in the majority of resources, despite having lower bioavailability. The 2020 Kidney Disease Outcome Quality Initiative guidelines recommend considering bioavailability of phosphorus source when implementing low phosphorus diets; current handouts in Canada would likely benefit from review.