Kidney Disease and Weight Loss
“Kidney Disease and Weight Loss” was written by Jen Hernandez RDN, CSR, LDN. Jen is a Registered Dietitian and Board-Certified in Renal Nutrition at Plant Powdered Kidneys.
While many people spend time, money, and effort towards weight loss, some lose weight simply from a diagnosis of kidney disease. And while kidney disease and weight loss aren’t always thought of as being intertwined, weight loss can be a crucial factor to pay attention to when caring for your kidneys.
Chronic Kidney Disease 101
Chronic kidney disease affects over 37 million people in the United States, and 1 in every 3 Americans are at risk for kidney disease.
Causes of Kidney Disease
There are many causes of chronic kidney disease, which is why it has become so prevalent in the United States. And while some are very familiar, not all are known.
The top cause of CKD is diabetes. Diabetes affects over 10% of the US population as of 2020. Prediabetes affects even more – 88 million people (that’s 34.5% of the US population) have diagnosed prediabetes.
Whether it’s type 1, type 2, or even pre-diabetes, uncontrolled blood sugar can cause damage to the delicate kidney filtration system.
For a diabetes diagnosis, a blood test of your glucose is usually the first step. A fasting blood sugar of over 126 mg/dL in two separate tests can confirm a diagnosis of diabetes.
Another type of blood test is the hemoglobin A1c (or A1c). An A1c of between 5.7 and 6.4% is classified as prediabetes. An A1c of 6.5% or greater is classified as a diabetes diagnosis.
Type 1 diabetes is also called “juvenile diabetes” as it is discovered in the early stages of childhood. This is due to the fact that the pancreas does not produce any insulin.
Type 2 diabetes, or “adult onset diabetes,” is typically diagnosed in adulthood. It is caused by a poor response to the insulin that is produced by the pancreas.
High blood pressure, otherwise known as hypertension, is the second top cause of kidney disease in the United States.
In 2017, the American Heart Association changed the blood pressure guidelines to become more strict in when to define a blood pressure as being excessive.
High blood pressure is defined as a reading of 130 mm Hg for systolic (the top number) and higher or 80 mm Hg and higher for diastolic (the bottom number). Both numbers do not need to be high to have high blood pressure.
This is the third highest cause of kidney disease in the United States. Glomerulonephritis is a condition in which the glomeruli, or kidney filters, are damaged. The damage
Many people with autoimmune diseases can develop kidney disease. Some examples include:
- Goodpasture’s syndrome
- Wegner’s disease
- IgA Nephropathy (Berger’s disease)
Other causes of kidney disease
Other causes of kidney disease include:
- Polycystic kidney disease (a genetic disorder)
- Nephrotoxic drugs
- Heavy metal poisoning
- Alport syndrome (a genetic condition)
Besides having one of the top causes of kidney disease, there are other factors that may increase your risk of getting kidney disease. Some of those factors are:
- Smoking or history of smoking
- Heart disease
- Family history of kidney disease, diabetes, or hypertension
- Being African-American, Native American, or Asian-American
- Sedentary lifestyle
- Being 60 years or older
- Any history of acute kidney injury (AKI)
As mentioned, many may not experience symptoms until the majority of their kidney function has been lost. However, symptoms of chronic kidney disease may include:
- Loss of appetite
- Shortness of breath
- Less frequent urination
- Changes in mental status
- Muscle cramping
- Swelling at the feet, ankles, hands, and even face
- Uncontrolled blood pressure
Diagnosis & Stages of Kidney Disease
Chronic kidney disease is diagnosed with blood and urine testing. Your primary care physician may test your kidney health routinely if you present with any of the risk factors.
The stages of kidney are listed in the table below.
|Stage of Chronic Kidney Disease||Kidney Health Status||Estimated Glomerular Filtration Rate (eGFR)|
|Stage 1||Kidney damage with normal kidney function||90 and higher|
|Stage 2||Kidney damage with mild function loss||60 – 89|
|Stage 3a||Mild to moderate kidney damage||45 – 59|
|Stage 3b||Moderate to severe kidney function||30 – 45|
|Stage 4||Severe loss of kidney function||15 – 29|
|Stage 5||Kidney failure||Under 15|
An estimated GFR is calculated using the serum creatinine level. To confirm a diagnosis of kidney disease, a test must be done on two separate occasions.
It’s important to note that the GFR will decline naturally in the aging process.
In a urinalysis, testing for albuminuria can also indicate the progression of chronic kidney disease.
Treatment for Kidney Disease
While chronic kidney disease is at this time incurable, there are many areas of treatment in management. Treating kidney disease upon discovery can also help in delaying or stopping the progression of this chronic illness.
One of the most common first steps in treating chronic kidney disease is changes to the diet.
Depending on the stage, cause, lab results, and symptoms of kidney disease, dietary modifications can help in better managing CKD.
The National Kidney Foundations’ Kidney Disease Outcomes Quality Initiative (KDOQI) updated their nutritional guidelines in 2020 to include support of a low protein diet in managing chronic kidney disease.
While it was previously believed that a low potassium diet was recommended for conservative management of chronic kidney disease, there is new information to suggest otherwise.
A more individualized approach is now recommended in determining the amount of potassium for a person with CKD. This can result in allowing more potassium to be consumed, which has shown benefits in managing blood pressure when paired with a low sodium diet.
Before restricting potassium, it’s advised that a person with chronic kidney disease see a registered dietitian for a comprehensive assessment and discussion of daily potassium allowance.
By partnering with a dietitian, a person can more safely manage both kidney disease and weight loss.
Once the kidney function starts to decline, there is potential for phosphorus buildup in the body. Excess phosphorus can cause problems with bones, increase risk for cardiovascular disease, heart attack and stroke, and increase risk for kidney transplant failure.
However, there are several ways to manage phosphorus with chronic kidney disease. Avoiding all phosphate additives by searching ingredient lists can help in preventing absorption of phosphorus.
Additives made from phosphates are absorbed 90-100% into the bloodstream, making them particularly dangerous.
If phosphorus remains uncontrolled with diet changes, a physician may prescribe a phosphate binder to help prevent absorption of phosphorus.
Similar to potassium, the amount of fluid recommended for someone with chronic kidney disease will depend on the individual.
In later stages of chronic kidney disease, edema is a more common complication. A fluid restriction may be advised by your healthcare provider in effort to keep kidney function.
In some cases, however, increasing fluid intake may be advised. Certain kidney diagnoses such as kidney stones, kidney infections, and polycystic kidney disease may warrant a fluid intake of over 3 liters per day.
Working with your healthcare team will help you determine the best amount of fluid you should aim for each day.
Certain risk factors for kidney disease are modifiable and can lower risk of or progression of chronic kidney disease.
One of the first – and best- things that can be done for kidney health is to stop smoking. Smoking increases the risk of end stage kidney failure and the need for dialysis. The risks of smoking are well known, and stopping smoking can help reduce the risk of chronic kidney disease and complications.
With the kidney doing so many jobs for our body, medications are often prescribed with kidney disease to help take over certain tasks the kidneys can no longer do.
Many people with chronic kidney disease are prescribed blood pressure medication such as angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs).
For people with diabetes, blood sugar management is very important in keeping kidneys as healthy as possible. Certain types of blood sugar medications, including insulin, may be prescribed.
It’s important to discuss all concerns about medications with your prescribing doctor.
Dialysis is the treatment method for people with end stage kidney failure.
Once a kidney is below 15% function, a person qualifies for dialysis initiation.
The process of dialysis includes cleaning the body of toxin buildup that the kidneys can no longer manage.
The toxin removal can be done either by cleaning through the blood or using the peritoneal (abdominal) cavity to pull toxins. There are several options for dialysis treatment. The most important factor in deciding treatment is understanding which one is best for you and your lifestyle.
The average waiting time for a kidney transplant is approximately five years, so it’s important to get on the waitlist as soon as possible. Once on the waitlist, monthly blood tests will be done to monitor kidney function.
After a kidney transplant, a transplant team will follow up and closely monitor the kidney function. There will be life-long anti-rejection medications that will need to be taken to prevent the kidney from being rejected by the body.
Kidney disease and weight loss
As several of the symptoms of kidney disease relate to how much we eat (for example, feeling nauseous or vomiting can lead to a low appetite), weight loss is often an eventual result with chronic kidney disease.
While weight loss can be good for us, it’s important to know that there are healthy ways and unhealthy ways when it comes to weight loss with kidney disease.
Healthy weight loss with kidney disease
For those with a overweight or obese body mass index (BMI), your doctor may encourage some weight loss to help manage your health conditions including kidney disease.
Healthy weight loss is generally seen as weight loss of one to two pounds per week. For those with over 100 pounds of weight to lose, aiming for approximately 1% weight loss per week may be acceptable.
An overall weight loss goal that can still show benefits can be anywhere from 5-10% of your current weight over the course of 6 months.
Benefits of kidney disease and weight loss
For those that have type 2 diabetes and kidney disease, intentional weight loss has been shown to help preserve kidney function.
Other benefits that have been found with weight loss for kidney disease include less protein in the urine (proteinuria) and lower systolic blood pressure.
Unhealthy weight loss with kidney disease
While there are some benefits of weight loss with kidney disease, there is also a risk of losing the wrong kind of weight.
If weight loss happens too quickly or unintentionally, it may lead to other health complications.
Sarcopenia is when a person loses muscle mass. This happens with the elderly but can also happen in people with serious health concerns such as cancer, heart, failure, and chronic kidney disease.
Another term for unhealthy weight loss with kidney disease is protein-energy wasting (PEW). This term also refers to the body using up protein stores from muscles in order to keep up with energy needs.
Protein-energy wasting is quite common with chronic kidney disease, especially those with end stage kidney failure. In one article, they found that 54% of a group of dialysis patients fell into the classification of PEW.
For other stages of kidney disease, weight loss to the extent of PEW grew from less than 2% of stages 1-2 to 11-46% in stages 3-5.
Risks of weight loss with kidney disease
Weight loss, when unintentional, can increase risk factors for other health complications.
Kidney disease is a highly active state for the body, in which more calories are needed to keep up energy levels.
Uremia and inflammation, as well as often the autoimmune causes of kidney disease, all contribute towards this higher level of caloric needs of the body.
When experiencing unintentional weight loss, it is important to discuss your current nutritional state with your doctor and dietitian. If you do not have a dietitian, you may be able to ask your doctor for a referral to one so you may have additional support in preventing further unintentional weight loss.
Significant weight loss
Significant weight loss is defined as weight loss exceeding in the following ranges:
|Time Period||Amount of Weight Loss (%)|
|1 week / 7 days||>2%|
|1 year / 12 months||>20%|
If you are losing weight at or above this range, this is defined as significant weight loss. It’s important to discuss this rate of weight loss with your doctor and healthcare team to ensure you are not risking malnutrition
Fluid weight loss with kidney disease
It’s important to know that weight loss or weight gain and kidney disease may be connected due to fluid balance.
The kidneys are responsible for making urine and controlling blood pressure. The amount of urine you make or don’t make is dependent on your kidney function, salt intake, and fluid balance.
If you make changes to your diet, either by cutting down on salt or cutting back on carbohydrates, you may experience drastic weight loss in the beginning.
However, once your body adjusts to the changes, your weight loss will gradually slow down. The initial weight loss you’ve experienced is water weight that has been released by not having as much salt in your diet or by the use of carbohydrate stores in your body, which release water when being used.
Many people with kidney disease require the use of diuretics.
These help to control blood pressure by creating more urine and helping to release extra fluid buildup.
It’s very important to take medications exactly as prescribed by your doctor as not following directions can lead to serious problems.
Dialysis weight loss
In dialysis, excess fluids are taken out of the body. A person’s weight is measured both before and after a dialysis treatment to measure the amount of fluid that was removed.
It’s important to know that this is not actual weight loss. Dialysis weight loss is the removal of the extra fluid that was collecting in the body due to the kidney’s inability to remove it on its own.
Actual weight is calculated based on the trends of the dialysis treatment weights as well as blood pressure and electrolyte balance. Your nephrologist and dialysis healthcare team including your nurse and dietitian will monitor your weight for real weight changes.
Tips to safely lose weight with kidney disease
If you have been encouraged by your healthcare provider to lose weight, here are some steps you can take in safely managing both your kidney disease and weight loss.
Try getting in more steps if you are able to walk! Walking is a great way to lose weight and create a consistent exercise routine that will not be hard on the body.
If you find walking to be unappealing, try pairing it with an enjoyable hobby. One of my clients enjoys walking while listening to old radio shows. He looks forward to his exercise so he can listen to more episodes!
Get in more fruits and vegetables
While many think they need to cut back on fruits and vegetables due to the potassium, it’s not always the case. Plus, there are plenty of low-potassium fruits and vegetables to choose from. Fruits and vegetables are low in calories but have a lot of nutritional value.
Choose snacks wisely
If you enjoy having a snack between your meals, make sure you are choosing something that will still support your kidney disease and weight loss goals!
Try some low-sodium snacks like these dietitian-approved snacks that you can find online or in the grocery store.
Another tip to finding snacks for kidney disease and weight loss is to focus on the fiber.
While kidney disease may change how much you should be drinking every day, it’s important to know what your right fluid goal is and aim for that each day.
Many people are consistently dehydrated from not drinking enough, and the risk of dehydration increases as we get older.
Ask your doctor if you need to be on a fluid restriction, or find out if you have a fluid goal to aim for. Only your doctor and dietitian can tell you how much fluid you should be drinking each day.
How to safely gain weight with kidney disease
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Add in heart-healthy fats
There are plenty of healthy fat sources in our diet that can add in calories! Fat has the highest calorie per gram volume compared to carbohydrates and protein, so adding in a few tablespoons can do a ton for weight gain for kidney disease.
Try adding in some coconut oil* to your morning oatmeal- just a teaspoon will do the trick! If you’re not a fan of coconut oil, you can use flaxseed oil* or ground flaxseeds*. Just be sure the flaxseed is not whole as we don’t digest those.
When roasting up some veggies, add an extra tablespoon of avocado or olive oil. Roasted vegetables, whether low or high potassium, is a great part of a kidney-friendly diet.
Try calorie-rich shakes
To boost the calories in your smoothies, try adding in some ground flaxseed or chia seeds.
One ounce (about two tablespoons) of chia seeds tacks on an extra 140 calories for only 115 milligrams of potassium. Keep in mind that seeds do include protein – about 5 grams here – so it’s important to factor that into your daily protein needs.
For the milk base for your shakes or other recipes, canned coconut milk has a high level of calories per cup.
Try a kidney-friendly nutritional shake
The nutrition company Abbott makes a kidney-friendly nutritional shake called Suplena* that is low in protein, potassium, sodium, and phosphorus. If you cannot keep weight on with food, consult with your dietitian or doctor about taking Suplena.
If you are on dialysis and need to gain weight, the same company has another dialysis-specific product called Nepro* that has more of the protein you need due to dialysis. You can ask your dialysis dietitian or nephrologist about the potential benefits of adding this to your dialysis treatment plan.
Skip the protein powders
In 2020, the Kidney Disease Outcomes Quality Initiative (KDIGO) from the National Kidney Foundation recommended that those with kidney disease not follow a high protein diet. In later stages of kidney disease (not on dialysis), protein recommendations can be as low as 0.4 grams per kilogram of body weight.
When it comes to safely adding calories, do not add protein powders if you have kidney disease. This may prevent weight loss but will do your kidneys no favors.
When it comes to kidney disease and weight loss, there is a safe way and an unsafe way to lose weight.
If your doctor and healthcare team is encouraging you to to lose weight for your kidney health, be sure to do so in a slow and steady way to keep your kidneys healthy. Working with a dietitian is a great way to help make sure everything goes smoothly for your weight loss goals.
Note from The Geriatric Dietitian: I wanted to thank Jen Hernandez for writing this amazing article for The Geriatric Dietitian community! If you want to learn more about real solutions for renal nutrition, visit Jen’s website, Plant-Powered Kidneys, and join her free Facebook Community!