Protein plays many important roles in the body. It helps you build muscle, supports healing, helps make important hormones, and fights infections to keep you healthy. When we eat protein, our bodies use what it needs, and the leftover waste products are carried through the bloodstream to the kidneys. Healthy kidneys act like a filter and help to remove waste from protein though urine. If you have kidney disease, your body may not be able to remove all the waste created from breaking down protein, which means your kidneys have to work harder to manage it. If excess protein waste builds up in your blood, it can cause nausea, loss of appetite, weakness, and taste changes. Because of this, understanding protein and CKD needs is an important part of not only your kidney health, but your overall health.
Protein needs and CKD by stage
Protein needs depend on many factors such as body weight, kidney function, presence of diabetes, as well as the stage of CKD. For this reason, individualized assessment is best for understanding what is right for you. The general recommendation is that protein should take up roughly ¼ of your plate. That’s about the size of a deck of cards.
Here are some more specific guidelines for protein and CKD:
For CKD stages 1 and 2, the general recommendation is to limit protein to no more than 0.8 grams per kilogram of body weight. An estimated way to calculate your daily maximum intake of protein in grams, multiply your weight in kilograms by 0.8.
For CKD stages 3 to 5, one may need to restrict their protein more to prevent wast products from building up. Recent studies show that limiting protein to 0.55-0.6 grams per kilogram of your body weight delays kidney decline. This is considered a very low protein diet and may require supplementation of keto-anologues to ensure you receive enough of the essential animo acids. Current recommendations from KDIGO continue to recommend 0.8 grams protein per kilogram at this stage, with a focus on plant-based proteins.
These guidelines are important to note because in North America, there is a large focus on increasing protein consumption in the media, and studies have shown that CKD patients may be over-consuming protein. Those living with CKD should avoid protein amounts greater than 1.3 grams per kilogram to prevent progression of kidney disease.
However, when someone begins dialysis, their protein needs increase. This is because dialysis removes some protein and amino acids from the body, so eating more protein helps maintain strength and healthy blood protein levels. At this stage, a low-protein diet is no longer recommended.
Protein and CKD common foods
Here are the amount of protein in some common foods when consuming protein and CKD.
- Cheese ¼ cup shredded or 1 oz (28 g) = 7 g
- Milk (1 cup) = 8 g
- Yogurt (100 g or ½ cup) = 4 g regular, 8 g Greek
- Cottage cheese (½ cup) = 14 g
- Egg (1) = 6 g
- 3 oz chicken, fish (3x/week), red meat (1x/week or less) = 21 g
- Beans (1 cup) = 14 g
- Peanut butter (2 tbsp) = 7 g
- Nuts (¼ cup) = 4 g
- Tofu (½ cup) = 10 g
Protein source and CKD
When you’re living with CKD, the type of protein you eat can be just as important as the amount. Protein comes from two main sources: animal foods and plant foods.
Animal protein sources include foods such as chicken, fish, eggs, beef, pork, and dairy. They are packed with all the essential amino acids your body needs, they are easy to cook, and you only need small portions to meet your protein needs. However, animal protein tends to create more waste products for your kidneys to filter out. They’re also higher in phosphorus which can build up in your body causing weak bones and hardened blood vessels. Furthermore, processed meats can be extremely high in sodium, which can cause added stress to your kidneys.
Plant proteins on the other hand, come from beans, lentils, tofu, tempeh, nuts, seeds, and grains such as quinoa or oats. Although they lack one or more of the essential amino acids, they produce fewer waste products, contain fibre, and their phosphorus is less easily absorbed by our bodies. They also support heart health! This is why it is important to consume plant-based proteins when possible.
Including more plant-based protein and CKD
Adding plant-based proteins to your meals doesn’t have to be complicated. The key is choosing the right portions and combining foods to meet your protein needs without overloading your kidneys. Here are some general tips to get you started:
- Mix and match
- Combine different plant protein sources, like beans with grains to ensure that meals supply all essential amino acids
- Watch portion sizes
- Be mindful of the portion sizes since plant-based proteins may be high in sodium or potassium
- Start small
- If you are want to start incorporating more plant-based proteins in your diet, start out by replacing meat in recipes with legumes or tofu once a week
- Cook smart
- Rinse canned beans or soak legumes in order to reduce potassium content
- Snack wisely
- Nuts and seeds are good sources of protein, but it’s easy to eat too much, which can increase protein intake beyond your target
Meeting your protein and CKD needs
Protein is important to keep us healthy and strong. But too much of a good thing with CKD can lead to reduced kidney function. To make sure you’re meeting your protein needs safely and effectively, work with a renal dietitian to create a personalized plan. Contact Kidney Nutrition today to get expert guidance tailored specifically to you.
This article was written by Kimia Oshagi, Nutrition Student Volunteer.
This article was reviewed by Emily Campbell, RD CDE MScFN.
