Kidney disease is a common problem affecting about 10% of the world’s population. The kidneys are small but powerful bean-shaped organs that perform many essential functions. When the kidneys aren’t working properly, they cannot filter and remove waste properly, which can then build up in the blood, leading to numerous metabolic complications.
The majority of these waste products come from food. Therefore, it is necessary for people with kidney disease to be mindful of dietary choices. Following a kidney diet may slow the progression of kidney disease and delay or prevent the need for dialysis.
A proper renal diet focuses on limiting protein and sodium, and other electrolytes, depending on the severity of kidney disease. Some people may also need to restrict fluid intake. Every person’s body is different, and certain medications can affect electrolyte balance. Therefore, each patient must work with a registered renal dietitian to develop a diet plan tailored to the patient’s needs.
What is the best overall dietary pattern for me to follow?
The best diet for overall health focuses on increasing fresh fruits, vegetables, legumes, and whole grains, completely eliminating processed foods and sodas, and limiting the amount of meat, poultry, fish, and dairy. One such example is the Mediterranean diet.
This diet increases the amounts of essential vitamins, minerals, and antioxidants that your body needs for optimal functioning. Fruits, vegetables, legumes, and whole grains are the only source of dietary fiber, which is the most deficient nutrient found in typical diets.
It is estimated that less than 5% of Americans consume the daily recommended amount of fiber per day. Fiber is important for normalizing bowel movements, improving gut health, lowering cholesterol, lowering blood sugar, and achieving a healthy weight.
What is the latest research on diet and kidney disease?
In 2020, the National Kidney Foundation released its Clinical Update in Nutrition which recommends increasing the intake of fruits and vegetables and suggests that plant-derived proteins are equal to animal-based proteins to maintain healthy kidneys.
Over the last few years, there has been mounting evidence that a whole-foods, low-protein, plant-predominant diet is optimal for preventing and slowing the progression of chronic kidney disease. A plant-predominant diet is defined as a diet in which at least 50% of protein is derived from plant-based sources.
Why is good nutrition important for people with kidney disease?
Making healthy food choices is important to us all, but it is even more critical if you have Chronic kidney disease (CKD). Good nutrition can help to:
✅ Provide energy to do your daily tasks
✅ Prevent infection
✅ Maintain muscle mass
✅ Maintain a healthy weight
✅ Slow down the progression of kidney disease
✅ Reduce the risk of other medical conditions, specifically heart disease
What are the basics of good nutrition?
A well-balanced diet gives you the right amounts of protein, calories, vitamins, and minerals each day. Eating a healthy diet, staying physically active, and taking all your medicines as prescribed are essential parts of keeping you healthy and feeling well.
Will I need to change my diet if I have kidney disease?
Your kidneys help to keep the right balance of nutrients and minerals in your body. But if you have kidney disease, your kidneys may not be able to do this job very well. You will need to make changes to your diet. For most people with kidney disease, old food habits have played a significant role in developing chronic kidney disease in the first place.
Ask your doctor about meeting with a Registered Dietitian with special training in kidney disease. A dietitian can teach you to make the best food choices based on your lab tests and personal lifestyle. Making changes in your diet to better control diabetes and high blood pressure can also help keep kidney disease from worsening.
Meeting with a dietitian is a covered service by Medicare. The service may also be a covered benefit by other types of insurance. You may need to call your insurance provider to find out if meeting with a dietitian is covered by your plan.
What kinds of changes will I need to make to my diet?
There is not one eating plan that is right for everyone with kidney disease. What you can or cannot eat may change over time, depending on how much kidney function you have and other factors. Also, if you are following a special diet for diabetes or heart conditions, you will need to continue following it.
People with kidney disease may need to control the amount of protein, sodium, potassium, phosphorus, and calcium in their diet. If your kidney disease gets worse, you may need to limit other nutrients as well. Your dietitian or healthcare provider will tell you if you need to do this based on your blood test results.
Your body needs protein to help build/maintain muscles, repair tissues, and fight infections. Unfortunately, one of the cornerstones of managing kidney disease is to reduce overall protein intake. Your kidneys are responsible for processing dietary protein. Therefore, reducing protein intake helps maintain kidney function because the kidneys do not need to work “overtime.”
As proteins are processed, waste products are created, which can build up due to your kidneys decreased ability to eliminate these toxins. The level of protein restriction is determined by your body size and the presence of other medical issues, such as diabetes.
In our current food environment, reducing overall protein intake can be challenging. Thus dietary protein deficiency is of little concern. Your dietitian or healthcare provider can tell you how much protein you should eat based on your individual needs.
Healthy kidneys control how much sodium is in your body. If your kidneys do not work well, too much sodium can cause fluid build-up, swelling, higher blood pressure, and strain on your heart. Your dietitian or healthcare provider can tell you the right amount of sodium you should have each day, but a good starting point is less than 2,000 mg per day.
Potassium works with the muscles, including the heart. In people with normal kidney function, diets high in potassium intake have been shown to help reduce blood pressure and reduce the risk of heart disease. Your kidneys are responsible for balancing potassium in your blood, and too much potassium can be very dangerous. For this reason, patients with kidney disease need to be mindful of potassium intake. The amount of potassium you are allowed depends on how well your kidneys are working. The better your kidney function is, the more potassium you can and should have. Medications, such as ACE inhibitors and aldosterone receptor blockers, can also alter blood potassium levels. Your dietitian or healthcare provider can tell you about foods with varying potassium levels and the right amount for you to eat each day.
As kidney function gets lower, extra phosphorus can start building up in the blood. High phosphorus levels can cause bones to get weaker as well as stiffen your blood vessels. Certain types of foods are very high in phosphorus, mainly processed foods, which should be eliminated as much as possible. Again, the level of phosphorus reduction is dependent on the severity of your kidney disease. Your dietitian or healthcare provider can review which foods you should avoid keeping phosphorus levels low.
Foods that are good sources of calcium are often high in phosphorus. Your dietitian or healthcare provider will tell you if you need to limit calcium. Talk to your healthcare provider before taking any over-the-counter vitamin D or calcium supplements.
Will I need to limit fluid?
Most people in the early stages of kidney disease do not need to limit the amounts of fluids they drink. If you do not know your stage of kidney disease, ask your healthcare provider. If your kidney disease worsens, your dietitian or healthcare provider can let you know if you need to limit fluids and how much to drink each day.
How many calories do I need?
Every person is different. Calories are like fuel. If you don’t eat enough calories, your body will use protein for energy. This protein comes from your muscles. This can make you weak and may also cause damage to the kidneys. It is vital to make sure you are getting the right amount of calories. The right amounts of calories are essential to:
Help you stay at a healthy weight
Give you the energy to do your daily tasks
Help your body use the protein in food to build muscle and tissues.
Too many calories can cause extra weight gain, which can be a burden on the kidney. If you are overweight, some weight loss may be beneficial. If weight loss is desired or you have diabetes, you should meet with a dietitian to set up a plan based on your kidney blood tests, current food choices, and daily activities.
Should I be taking any vitamin and mineral supplements?
Most people get enough vitamins and minerals to stay healthy by eating a variety of foods each day. You need to limit some foods because you have kidney disease that would have given you vitamins and minerals. If so, you may need to take particular vitamins or minerals. You should only take the vitamins, and minerals your dietitian or healthcare provider tells you to take because some may be harmful to people with kidney disease.
You should check with your healthcare provider before taking any medications you can buy without a prescription. Some over-the-counter medications may be harmful to people with kidney disease. You should also avoid taking herbal supplements.
Why is a plant-predominant diet optimal for kidney disease?
When it comes to kidney disease, plant-predominant diets are crucial for particular reasons. As mentioned earlier, protein restriction is significant in managing kidney disease. Animal-based proteins are inherently higher in protein when compared to plant-based proteins.
By increasing the consumption of plant-based proteins, you can eat more food overall. Fruits and vegetables may have higher amounts of potassium, so careful selection of which foods to eat may be necessary and discussed with your dietician or healthcare provider.
Additionally, animal-based proteins are much higher in phosphorus, which also needs to be limited if you have kidney disease. One of the other complications of kidney disease is the build of acid in the blood, leading to muscle loss and weak bones. The foods that create the most amount of acid in your blood are meat and dairy, especially cheese. Plant-predominant diets help to reduce this acid build-up.
Plant-predominant diets have also been shown to reduce the risk of heart disease, the impact of which becomes more significant the higher percentage of plant-based foods you can eat. Many people who have switched to 100% plant-based diets have reversed diabetes, high blood pressure, high cholesterol and come off many medications.
Many doctors and renal dieticians may not be up fully up-to-date on the benefits of a plant-predominant diet, as this is a relatively new and emerging modality for helping kidney patients manage their disease. This will change over the coming years as more and more healthcare providers learn about it.