According to the CDC, one in every three American adults with diabetes also has chronic kidney disease. That is tens of thousands of people, all of whom are now dealing with not one but two challenging diseases, each of which has their own guidelines, restrictions, and recommendations in regards to diet and lifestyle.
It’s also believed that 40% of patients with type two diabetes will eventually develop chronic kidney disease. In 2013, that translated to more than 50,000 new cases of kidney failure from diabetes alone.
These are scary statistics, and it’s easy to understand why they can feel overwhelming when learning to navigate the world of renal diabetic diets. What works for one condition, chronic kidney disease, may not work for the other, diabetes, and you may find yourself stuck between two sets of recommendations.
But, with the right understanding of both conditions and the dietary options needed to manage them, implementing a renal diabetic diet doesn’t have to be a stressful experience.
Table of Contents
Understanding Kidney Disease & Diabetes
Implementing a renal diabetic diet starts with understanding chronic kidney disease, diabetes, and how these two conditions can be related. Since a renal diabetic diet is a diet that takes into account both a diabetes and chronic kidney disease diagnosis, it is important to understand both before embarking on a change in your dietary habits.
As with any dietary change, it’s best to work with your doctor and a registered dietitian to make these changes.
Chronic Kidney Disease occurs when your kidneys are no longer able to filter like they should. There are different stages of CKD, with early stages and later stages differing based on how well your kidneys can filter waste.
This is measured by your eGFR, or estimated glomerular filtration rate, and different eGFR levels correspond to the different stages of CKD.
Diabetes mellitus, on the other hand, is a disease of the pancreas where the body’s ability to make or respond to the hormone insulin is impaired. There are two main types of diabetes, type 1 and type 2.
In type 1 diabetes, the body doesn’t produce insulin like it should, leading to an increase in blood sugar that can reach dangerous levels.
In type 2, on the other hand, the body doesn’t respond well to the insulin that the body does produce, leading to high blood sugar and other potential complications.
Type 1 diabetes is an autoimmune condition that is normally present in early childhood, while type 2 diabetes occurs mainly in adults and older children or teens.
Some people with diabetes are more likely to develop CKD than others. That includes people with high blood pressure, poor glucose control, genetic factors, and diet.
This makes diagnosing these conditions very important. Elevated A1C can lead to the progression of chronic kidney disease, as can high blood pressure often seen in patients with type 2 diabetes.
Inflammation caused by the release of proinflammatory cytokines also leads to the progression of CKD, which can ultimately lead to end stage renal disease or even death.
Tests to diagnose kidney disease include those to look for protein in a patient’s urine, however the levels required to make a diagnosis may be different in patients with type one and type two diabetes.
That’s because patients with type 1 diabetes can often be diagnosed when there are very small amounts of protein found in the urine.
What is a Renal Diabetic Diet?
While most diets that are beneficial for diabetes are great for the general public, focusing on lean meats and vegetables, these diets may not be right for someone with CKD. That’s because they don’t tend to take into account things like the amount of phosphorus or potassium in the diet, and may not account for sodium.
On a renal diabetic diet, there are more things to take into account than with a general diet for diabetes. That includes carbohydrates, proteins, fats, and nutrients like potassium.
Carbohydrates are extremely important and beneficial for a renal diabetic diet. Certain foods, known as low-glycemic foods, may help improve overall blood sugar control and decrease postprandial hyperglycemia.
Low-glycemic foods are identified using the glycemic index, or a measure of the effect of the carbohydrates in food on your blood sugar. Examples of low glycemic foods include quinoa, oats, and wild rice.
In addition to low-glycemic foods, eating foods that are rich in fiber is important for a renal diabetic diet. Fiber is the non-digestible portion of plant foods, such as fruits and vegetables, and includes two different types – soluble fiber and insoluble fiber.
Fiber has been shown to help manage blood sugar as high fiber foods cause a much lesser insulin response than does glucose.
Fiber in the form of prebiotics has also been shown to aid in overall digestion. Prebiotics are part of the plant fiber that feed the good bacteria in your gut and promote a healthy microbiome.
Lean and Plant Proteins
Protein is considered the building block of our cells, but protein intake recommendations vary greatly depending on the stage of kidney disease and overall kidney function.
That is why it is important to make sure you are focusing on a renal diabetic diet, as opposed to simply a diet focused on managing diabetes, when you’re dealing with both conditions.
There are certain markers of eGFR you can look for when determining how much protein to eat in a day. The chart below will help you decide what amount of protein is best for you. This is also a great opportunity to work with a registered renal dietitian, as they are trained to understand your personal levels and make recommendations that are safe for you.
- <50 mL/min per 1.73m2
- <20 mL/min per 1.73m2
- Diabetic Nephropathy
Daily Recommended Protein Intake
- 0.6 – 0.8 g/kg
- 0.4 – 0.6 g/kg
- 0.8 – 0.9 g/kg
- 1.2 – 1.4 g/kg
It is very important to work with a dietitian when following a lower-protein diet (defined a less than 0.8 g/kg per day). Information here can also be found on the article, Dietary Protein Intake and Chronic Kidney Disease.
Some research has shown that limiting protein intake during the early stages of chronic kidney disease may lead to better overall outcomes in levels such as fasting glucose and eGFR. Limiting this nutrient, however, should only be done under the guidance of a registered dietitian.
Protein can be found in both animal and plant based foods. Examples of kidney friendly protein sources from animals include lean beef, turkey and chicken, though pre-made chickens that have been roasted should be avoided as they often contain more sodium and phosphorus. Cottage cheese, a dairy source of protein, is also a great option as it can be lower in potassium and phosphorus than other food choices.
Plant based protein options include tofu, lentils, nuts, and nut butters. As with all processed protein options and food choices, be sure to keep an eye on the amount of sodium in these foods and all foods you choose.
Fats often get a bad name, but fats are essential for our body to function properly. Not only do they help to insulate our bodies, they are also necessary for the formation of hormones and help to create healthy cells.
It’s also important to manage the type and amount of fat you’re consuming as part of a renal diabetic diet. While some fats can be beneficial, such as unsaturated fats discussed below, others, like excessive saturated fats or trans fats, can lead to increases in blood pressure, a dangerous condition for people with diabetes and chronic kidney disease.
Fats can be organized into a few different categories, including saturated and unsaturated fats.
Saturated fats are solid at room temperature and are found in foods like whole milk dairy, cheese, and many baked goods.
Unsaturated fats, on the other hand, are liquid at room temperature and come from vegetables, nuts, seeds, and fish.
Unsaturated fats can be organized into two groups, too. These are monounsaturated fats found in foods such as avocados and olive oil, and polyunsaturated fats, found in fatty fish and some oils.
Polyunsaturated fats are considered essential because our bodies can’t make them on their own, and we need to get them from our diets.
Two types of polyunsaturated fats, omega-3 and omega-6 fats, are important for managing high cholesterol, a condition that can be linked to diabetes and high blood pressure.
These fats have been shown to decrease LDL cholesterol, and can help reduce blood pressure (omega-3) and protect against heart disease (omega-6). Some people even benefit from an Omega-3 supplement, something we’ll discuss more below.
Potassium is not something that is normally limited in a traditional diabetic diet, but those on a renal diabetic diet should focus on their potassium when choosing foods.
This is because your kidneys may not be able to process the potassium in your food as well when you have CKD, and limiting your potassium intake is important for managing your disease.
When instructed by your physician, people with chronic kidney disease may need to aim for 3,000 mg to 4,000 mg of potassium per day, while people in end stage renal failure should aim for between 2,000 mg and 3,000 mg.
Common sources of potassium include dairy, nuts, and produce, all of which are great foods to include in your overall healthy diet in a way that fits your potassium needs.
Restricting your potassium in a kidney friendly diet should only be done if instructed by your doctor, but know that restricting doesn’t necessarily mean eliminating foods you enjoy.
Fruits are still an option on a low potassium diet, and understanding the factors that affect your potassium are also important when choosing the right foods for you.
Foods to Limit on a Renal Diabetic Diet
While a renal diabetic diet offers a lot of great options when it comes to food choices, there are some things that should be limited or eliminated. Many of these items are foods that should be limited in a general healthy diet, as well.
Sugar can be tough to limit in your diet, as it’s found in a variety of foods, from fruits and vegetables to processed food products. Understanding sugars, though, can make limiting and choosing the right foods a bit easier.
Simple sugars are just that – they’re sugars that are easy for our bodies to breakdown. These can be found in foods such as white breads, white pastas, pastries, soda, or candy, which are known as refined carbohydrates.
These sugars have been linked to type 2 diabetes, and should be limited as they are lacking in nutrients and fiber.
Fructose is another type of sugar that is found in fruit. While fructose is still sugar, it is often found alongside fiber, which helps to manage blood sugar. For people managing their sugar, fruit can be a great option for something sweet.
Artificial sweeteners are often misunderstood. These sweeteners, such as Truvia, are manufactured and added to foods to help improve the flavor while limiting the amount of sugar.
These artificial sweeteners are often much sweeter than their natural counterparts, and you may find you need much less of them to obtain the same taste.
While artificial sweeteners can be a good option for treats or sweets you don’t eat regularly, they shouldn’t be incorporated as a regular part of your diet.
Some studies have suggested that the consumption of artificial sweeteners may lead to an increased desire for sugar overall.
Saturated and Trans Fats
While some fats are beneficial for our health, others are not. Saturated fats, like we discussed before, and trans fats are two types of fats that should be avoided in a renal diabetic diet.
Saturated fats are found in foods like red meat, whole milk, butter, and lard, while trans fats are found in commercially processed snacks and baked goods. These fats have been known to raise blood cholesterol and may not be beneficial for heart health.
As people with CKD are at an increased risk of heart attack or stroke, it’s ideal to opt for heart healthy fats like monounsaturated or polyunsaturated fats instead.
Phosphorus is a mineral found in our foods and our body. It actually pairs with calcium to help form our bones! Organic phosphorus is found in our foods, like chicken, fish, eggs, and nuts. Phosphorus additives, however, are inorganic forms of phosphorus often added to foods as a preservative.
These additives can increase the levels of phosphorus in your blood, something that is dangerous for someone with CKD.
Phosphorus additives can be listed on ingredient labels as additives, including:
- Dicalcium phosphate
- Disodium phosphate
- Monosodium phosphate
- Phosphoric acid
- Sodium hexameta-phosphate
- Trisodium phosphate
- Sodium tripolyphosphate
- Tetrasodium pyrophosphate
Organic phosphorus is not something that is limited on a diabetic diet, but it is something you need to be aware of as a patient with CKD. Thankfully, many of the foods that have phosphorus additives are not a good source of nutrients, anyway, and should ideally be avoided in any healthy diet.
Limiting your sodium intake can be beneficial for your diabetes, your kidney disease, and your overall health. Sodium intake has been linked to high blood pressure, which is one of the main predictors of people with diabetes developing CKD.
Stick to 1,500 mg to 2,300 mg per day of sodium, depending on your disease and needs, but be sure to work with a professional when deciding how much to limit your sodium intake – very low sodium intake has been associated with impaired glucose metabolism and insulin sensitivity, two things that are a challenge for patients for diabetes.
Supplements for a Renal Diabetic Diet
Adding supplements into your daily routine is a personal choice and should be based on your personal dietary and health needs. Working closely with your renal dietitian can help identify if supplements, such as probiotics or multivitamins, are good options for you.
Multivitamin vs Renal multivitamin
Adding a multivitamin to your daily regimen can help you bridge the gap of nutrients that you may be missing in your diet.
You may be able to take a standard daily multivitamin, but as with all medications, it’s important to first discuss with your doctor. Your dietitian will also be able to help determine if you can use a standard multivitamin or if you should instead take a kidney-specific multivitamin.
For patients who need support specific to their renal health, a renal focused multivitamin may be a better option than a traditional, over the counter supplement. This is because it allows you to better control the amount of nutrients, such as phosphorus and potassium, you are supplementing in order to maintain your renal health.
My favorite renal MVI is ProRenal +D and omega-3s. I recommend this option because it covers a lot of bases for those with CKD, without the extra nutrients that the kidneys have a harder time filtering out (like vitamin A).
Remember, when selecting a supplement, work with your medical team or registered dietitian to determine which is best for you.
Adding a probiotic supplement to your diet can help improve both your gut health and overall wellbeing. Gut health has been linked to many aspects of health, including insulin sensitivity, and should be a priority for everyone, including those on a renal diabetic diet.
My preferred probiotic is Renadyl. This is because it is specifically formulated to support urea waste management with healthy bowel movements.
Medication Considerations for the Renal Diabetic Diet
Any medication changes should be discussed with your healthcare provider. Please do not make changes to your medications without first consulting your physician.
There are a number of different medications that may be recommended for a patient on a renal diabetic diet. This may vary depending on the severity of each individual disease, however medications for diabetes often have an effect on the kidneys that needs to be taken into account.
For example, a medication such as Metformin may be recommended to help manage your blood sugar levels if these are an issue.
Metformin, though, is not normally used in patients with an eGFR of less than 45 and should not be used in patients with an eGFR for less than 30 due to the risk of lactic acidosis.
If you want medical input about the safety of your medications related to your kidney health, ask your nephrologist to review your diabetic medication list.
Some patients with both chronic kidney disease and diabetes will need insulin, but the recommendations for dosing should be made based on the stage of kidney disease and the need of the patient. There is no one size fits all recommendation, however guidelines are available and may cover the below:
- There are no dose adjustment requirements if your GFR is >50 mL/min.
- The insulin dose should be reduced to approximately 75 percent of baseline when the GFR is between 10 and 50 mL/min.
- The dose should be reduced by as much as 50 percent when the GFR is <10 mL/min.
- Januvia / weekly injections should be adjusted based on renal impairment.
As always, be sure to consult with your physician before making any changes to your medication.
Navigating a diagnosis of both chronic kidney disease and diabetes may feel overwhelming at first. But finding dietary options to fit your needs doesn’t have to be. Working with a renal dietitian can help you create a plan that works best for you, while still allowing you to enjoy foods that you find enjoyable and satisfying.