by Coach Anna for the Kidney Cancer Association
Kate Zalewski, RDN, CSR, LDN is an experienced renal dietitian who owns a virtual private practice primarily helping people with chronic kidney disease delay or avoid dialysis. KCA Ambassador Annamarya Scaccia spoke with her about misconceptions around nutrition and kidney health, eating to build muscle, and how to protect your kidneys while pursuing fitness.
Annamarya Scaccia: As a fitness and nutrition coach, I worked specifically with kidney cancer survivors or people concerned with kidney health. And the one complaint I always here when they first come to me is that they won’t build the muscle they want if they can’t eat a high-protein diet. Now, as a competitive bodybuilder, I know that’s not true. But help me dispel this myth.
Kate Zalewski: There is a misconception that you must be on an insanely high protein diet to build muscle. But building muscle is about more than just the amount of protein consumed in a day. One thing to consider is proper timing of protein intake in proximity to your workouts to promote muscle growth. When you have a smaller amount of protein to work with, being strategic with timing of protein intake around strength training becomes even more important. Another factor to consider is not food-related at all. You also need to ensure you are following the right type of strength training program that will help you reach your body composition goals. Just winging it and hoping you’ll build muscle without a concrete plan on how to get there is not likely to get results.
Annamarya Scaccia: What do most coaches and dietitians get wrong about protein and kidney health?
Kate Zalewski: There are several myths out there about protein and the kidneys. One myth is that protein is damaging to healthy kidneys or can cause kidney problems in healthy people. For people without reduced kidney function, we just don’t have evidence that high protein intake alone contributes to kidney damage. Another myth is that a kidney-protective diet should be as low in protein as possible. This is not true. We need a baseline amount of protein—it is a nutrient, after all! But I see many clients who are afraid to eat any protein foods at all. Being overly restrictive on protein could be just as dangerous (if not more) than overdoing it, leading to conditions like protein energy malnutrition. Finally, there is a persistent myth that plant proteins are not a good option for kidney health. This is because plant foods (including plant proteins) are often high in potassium and phosphorus—two nutrients that could potentially become elevated in the blood when the kidneys are damaged. However, the need of any nutrients for the kidneys is very dependent on the individual’s labs. There is not one single “kidney diet.” Also, based on current evidence, the phosphorus from plant foods is minimally absorbed and doesn’t have much impact on blood phosphate levels. And potassium from the diet likely has little impact on blood potassium levels. There are many things besides diet that could impact potassium in the blood.
Annamarya Scaccia: Why do you think such misconceptions exist when it comes to renal nutrition?
Kate Zalewski: Renal nutrition is challenging because there is simply a lot of outdated info out there still floating around, doctors perpetuate a lot of that outdated info, and there is no one single kidney diet. The dietary needs can look different based on the extent of the disease or damage and an individual’s lab values, so it’s easy to get confused and overlook the nuance of the individual situation. This is why working with a kidney specialist dietitian is so helpful because they can help you understand your labs and needs, and tailor a diet exactly right for you.
Read the rest of the interview over at the Kidney Cancer Association's blog.