What is Chronic Kidney Disease (CKD)?
Chronic Kidney Disease (CKD) is the gradual decline of kidney function over time. Approximately 37 million adults (15% of U.S. adults) have CKD, and millions more are at risk. Without regular medical check-ups, it is possible to lose 90% of kidney function without noticeable symptoms.
When kidney function declines, waste products, excess nutrients, and fluids accumulate in the body, leading to various health issues.
There are five stages of CKD, ranging from Stage 1 (mild damage with normal kidney function) to Stage 5 (kidney failure requiring dialysis or transplant). Early detection and proper nutrition management can slow disease progression and prevent kidney failure.
This article focuses on nutrition management for CKD and how personalized nutrition can help preserve kidney function.
How is Kidney Function Measured?
Doctors use blood tests to determine kidney function, including:
1. Estimated Glomerular Filtration Rate (GFR)
A measure of kidney function that indicates how much blood the kidneys filter per minute. eGFR determines CKD stage.
A waste product from muscle metabolism used in the formula to determine GFR. Factors like age, weight, height, gender, and race may also be considered.
2. Blood Urea Nitrogen (BUN)
A waste product created when protein is broken down into amino acids and metabolized into ammonia.
The liver converts ammonia into urea, which is filtered by the kidneys. CKD impairs this process, leading to elevated BUN levels.
3. Creatinine
Produced by normal muscle function, creatinine is filtered by the kidneys and eliminated in urine. CKD results in creatinine buildup in the blood.
4. uARC: Urine albumin-creatinine ratio
- Albumin – an important protein normally found in the blood. It serves many roles in the body – building muscle, repairing tissue, and fighting infection. It is not usually found in the urine.
- Creatinine – a waste product that comes from the digestion of protein in your food and the normal breakdown of muscle tissue. It is removed from the body through the kidneys and is expected to be found in the urine.
Healthy kidneys prevent most albumin from passing through their filters and entering the urine, keeping levels very low or nonexistent.
However, when the kidneys are damaged, their filtering ability is compromised, allowing albumin to leak into the urine, which may be a sign of kidney disease.
Know Your Numbers: Take a Proactive Approach
Understanding your kidney function numbers is crucial for taking control of your health. Many people are unaware of their kidney status until they reach Stage 3 or beyond, when significant damage has already occurred.
By regularly monitoring your GFR, creatinine, and BUN levels, you can detect early changes and take proactive steps to slow CKD progression.
Ask your doctor to explain your lab results and what they mean for your kidney health. The more informed you are, the better equipped you’ll be to make lifestyle and dietary choices that help preserve kidney function for the long term.
What Causes Chronic Kidney Disease?
The two leading causes of CKD are:
1. Diabetes (Type 1 & Type 2)
High blood sugar damages the tiny blood vessels in the kidneys, reducing their filtering ability. Over time, this can lead to kidney failure. Therefore, it is of utmost importance to maintain tight blood sugar control.
2. Hypertension (High Blood Pressure)
Increased blood pressure damages kidney blood vessels, leading to scarring and reduced function.
Other causes include:
- Glomerulonephritis: Inflammation of kidney filtering units
- Polycystic Kidney Disease (PKD): An inherited disorder
- Autoimmune Diseases (e.g., Lupus)
- Fetal Malformations
Who is at Higher Risk for Chronic Kidney Disease?
Certain populations are at greater risk of developing CKD:
- People with diabetes or hypertension
- Those with a family history of CKD
- Older adults (over 60)
- African American, Hispanic, Asian, Pacific Islander, or Native American descent
- Individuals with obesity, smoking habits, or frequent NSAID use
Symptoms & Diagnosis of Chronic Kidney Disease
Early CKD often has no symptoms, making routine testing essential. As kidney function declines, symptoms may include:
- Frequent or painful urination
- Swollen eyes, hands, and feet
- Fatigue and low energy
- Muscle cramps (especially at night)
- Poor appetite, nausea, or vomiting
- Dry, itchy skin
- High blood pressure
- Blood or protein in the urine
Stages of CKD
CKD is classified into five stages based on GFR levels:
| CKD Stage | GFR (mL/min) | Severity |
|---|---|---|
| Stage 1 | > 90 | Normal or High GFR |
| Stage 2 | 60-89 | Mild CKD |
| Stage 3A | 45-59 | Moderate CKD |
| Stage 3B | 30-44 | Moderate CKD |
| Stage 4 | 15-29 | Severe CKD |
| Stage 5 | < 15 | End-Stage CKD (Kidney Failure) |
Nutrition Tips for Chronic Kidney Disease
Optimized nutrition is key to slowing CKD progression and maintaining kidney function. Depending on the stage of kidney disease, your dietary needs will vary.
This is why it’s essential to work with a Registered Dietitian Nutritionist (RDN) for personalized nutrition recommendations tailored to your medical needs. General recommendations include:
Control Blood Sugar & Blood Pressure
- Choose low-glycemic foods like whole grains, legumes, and vegetables.
- Limit added sugars, processed foods, and excessive sodium.
Reduce Sodium Intake
- Aim for less than 2,300 mg of sodium per day (or lower based on doctor’s advice).
- Avoid processed and fast foods; opt for fresh, whole foods instead.
Eat Kidney-Friendly Proteins
- Too much protein can strain the kidneys.
- Choose lean meats, poultry, fish, eggs, and plant-based proteins in moderation.
Monitor Potassium & Phosphorus Intake
- High levels of potassium and phosphorus can be harmful for patients with chronic kidney disease.
- Limit high-potassium foods like bananas, oranges, potatoes, and spinach.
- Limit high-phosphorus foods like dairy, sodas, and processed meats.
Stay Hydrated
- Drink adequate water to help flush toxins, but avoid excessive fluid intake if advised by a doctor.
Limit Processed Foods & Sugary Drinks
- Processed foods contain excess sodium, phosphorus, and unhealthy fats.
- Replace sodas with water, herbal tea, or infused water.
Following a “kidney” diet can be challenging due to its many dietary restrictions. Overly strict diets should be avoided, as they may lead to inadequate nutrient intake. For individuals with a GFR of 60 ml/min/1.73 m² or higher, significant dietary changes are typically unnecessary.
Instead, they should follow general healthy eating guidelines, limiting sodium and added sugars while emphasizing fruits, vegetables, legumes, fish, poultry, whole grains, and reducing red and processed meats.
However, as CKD progresses, dietary adjustments become essential based on disease stage, potential renal replacement therapy, and the presence of other health conditions.
Plant-Based Diets & Kidney Disease
A plant-based diet may help reduce the risk of chronic kidney disease (CKD) by addressing its primary causes, including hypertension, type 2 diabetes, and metabolic syndrome, which are prevalent in America.
Research suggests that plant-based diets (PBDs) lower the risk of kidney damage by improving metabolic health and reducing disease risk factors. Similarly, the DASH diet, known for its emphasis on fruits, vegetables, whole grains, and lean proteins, has been shown to have a protective effect against CKD.
Among plant-based diets, the vegan diet, which eliminates animal products entirely, may offer the greatest benefits for CKD prevention by further reducing dietary risk factors associated with kidney disease.
Take Action: Protect Your Kidney Health
The earlier you take action, the better your chances of slowing CKD progression and preventing kidney failure. At Core Nutrition Health and Wellness, our expert Registered Dietitian Nutritionists (RDNs) create customized kidney-friendly nutrition plans tailored to your unique health needs.
Whether you’re managing CKD, diabetes, or high blood pressure, we provide the guidance you need to make informed food choices and slow disease progression. Take control of your kidney health—schedule your consultation today and let your insurance cover the cost.