Fast food, phosphorus-containing additives, and the renal diet

Fast food is commonly consumed by hemodialysis patients, but many menu items are not compatible with renal diets because of their sodium, potassium, or phosphorus content. Moreover, the phosphorus content of fast foods is difficult for patients to estimate, because phosphorus-containing additives are commonly added to many fast foods. We sought to determine how many fast-food entrees and side dishes are compatible with renal diets.

We examined nutrition-facts labels and ingredient lists provided by 15 fast-food chains. Each entree and side dish was first assessed according to traditional criteria (limited sodium, potassium, and naturally occurring phosphorus content), and then according to the presence of a phosphorus -containing additive.

Of 804 total entrees across all restaurants, 415 (52%) were acceptable according to traditional criteria, but only 128 (16%) were also free of phosphorus-containing additives. Of 163 total side dishes, 37 (23%) were acceptable according to traditional criteria, and 27 (17%) were also free of phosphorus-containing additives. There were no acceptable entrees at 3 chains, and no acceptable side dishes at 5 chains.

Only a small proportion of fast-food entrees and side dishes are compatible with renal diets. The widespread use of phosphorus-containing additives is a major impediment to the availability of acceptable fast-food choices for hemodialysis patients. We recommend limiting the use of phosphorus-containing additives, and including phosphorus content in nutrition-facts labels.