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Kidney Disease and Weight Gain: How Are They Linked?

Written by Andrew Le, MD

UpdatedFebruary 28, 2024

Kidney disease is a progressive condition impacting over 800 million people worldwide. This condition is more prevalent in older adults, women, racial minorities, and those with diabetes or hypertension.

Kidney disease and weight gain are linked because as obesity escalates, it brings about related health issues like high blood pressure and diabetes, increasing the risk of developing chronic kidney disease (CKD).

This article will help you understand what kidney disease is, its risk factors, signs and symptoms, and prevention, where we'll discover the connection between kidney disease and weight gain.

🔑 Key Takeaways:

  • Obesity isn't a direct cause of kidney disease but contributes through pathways like high blood sugar, high blood pressure, fluid retention, calcium retention, and renal hyperfiltration.
  • Obesity can cause the body to retain too much fluid, lead to mineral imbalances, and result in vitamin shortages. All these factors can stress the kidneys and increase the risk of kidney disease.
  • The kidneys play an important role in filtering blood waste, and their function becomes compromised when external influences or underlying illnesses damage their nephrons, resulting in kidney diseases such as CKD.
  • Signs and symptoms of kidney disease can include abnormal protein levels in urine, high blood pressure, swelling, and fatigue, but many may not manifest until the disease has advanced.
  • Preventing obesity-related kidney disease involves lifestyle changes like reduced salt intake, regular exercise, and avoiding certain medications.
  • Maintaining a healthy weight is crucial for kidney health, as obesity increases the risk of conditions that can damage these vital organs.
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Understanding Kidney Disease

Kidney or renal disease happens when the kidneys can't function effectively.

Kidney disease can manifest in several ways, including acute kidney injury (a sudden loss of kidney function often caused by factors like severe infections or medication reactions) and CKD (a long-term condition where the kidneys gradually lose their ability to function).

To learn more, let's examine the types of kidney disease and their signs and symptoms.

Types of Kidney Disease

When the kidneys are compromised, various types of kidney diseases can emerge, each with its own set of challenges and implications, such as the following:

  • Focal segmental glomerulosclerosis (FSGS): This is a disease where the kidney's filtering units (glomeruli) are scarred, leading to nephrotic syndrome and kidney failure.
  • Kidney stones: This is when hard crystals form in the kidneys, which can cause pain and block urine flow.
  • Albuminuria/Proteinuria: This disease has increased albumin or protein in the urine, indicating kidney damage.
  • Acute kidney injury (AKI): People with obesity are at a higher risk of AKI, where the kidneys suddenly stop working.
  • Renal cell carcinoma: Kidney cancer starts in the cells lining the kidney's tiny tubes.
  • Chronic kidney disease (CKD): CKD is the most common obesity-related kidney disease, with diabetes and high blood pressure being its main triggers.

Signs and Symptoms of Kidney Disease

Recognizing the symptoms of kidney disease is crucial for timely intervention. Most of them often develop slowly over time.

Here are the signs and symptoms to help you detect kidney disease if you're obese:

  • Blood and urine tests: These tests can detect abnormal levels of proteins, creatinine, or other substances that indicate kidney dysfunction. These measure your kidney function and helo determine what stage of kidney disease you have.
  • High blood pressure: Obesity raises the risk of hypertension, which, in turn, is a leading cause of kidney disease. If you're obese and struggling to control your blood pressure, it might be a sign of kidney issues.
  • Swelling: Fluid retention causing swelling in the ankles, feet, hands, and face can be a sign of kidneys that don't function properly. This means the kidneys cannot remove extra fluid from the body.
  • Changes in urination: This could be more frequent urination, especially at night; foamy or bubbly urine; blood in the urine; or difficulty urinating.
  • Fatigue: Erythropoietin is a hormone produced by healthy kidneys. It prompts the body to create red blood cells. Damaged kidneys produce less, leading to anemia and fatigue.
  • Other symptoms: These can include shortness of breath, nausea, loss of appetite, a metallic taste in the mouth, or cold extremities. However, the manifestations can differ across various stages of kidney disease, especially CKD.

Kidney Disease And Gain Weight

Kidney disease can cause weight gain, but it's not the typical weight gain associated with obesity.

In individuals with kidney disease, weight gain is often a result of fluid retention rather than an increase in fat or muscle mass.

The kidneys play a crucial role in regulating fluid balance by removing excess fluid from the body through urine. When kidneys are compromised, as in kidney disease, they may not effectively remove this excess fluid, leading to fluid retention and weight gain.

Damaged kidneys struggle to convert excess fluid into urine, causing the accumulated fluids to build up in the body. Since one liter of water weighs about 2.2 pounds, even a moderate increase in fluid retention can contribute significantly to the numbers on the scale.

Unlike obesity-related weight gain, changing eating habits alone may not alleviate the weight gained due to kidney disease. Improvement in kidney function or specific treatments like taking diuretics or undergoing dialysis may be required to address fluid retention and reduce weight.

Now, let's explore the information below to understand further how kidney disease and weight gain are linked.

Obesity's Role in Kidney Disease Risk

While obesity doesn't directly cause kidney disease, it significantly contributes to factors that increase the risk of developing kidney disease.

The primary causes of kidney disease include:

  • Diabetes
  • High blood pressure
  • Genetic mutations
  • Infections
  • Exposure to toxins

🗒️ Related Articles

Type 2 diabetes is a prevalent condition influenced by various lifestyle and genetic factors. Learn more about this condition and how to avoid and treat it.

Obesity contributes to an increased risk of diabetes and high blood pressure, making it a significant indirect factor in developing kidney disease.

Lifestyle choices such as inactivity and an unbalanced diet associated with obesity can elevate the risk of developing conditions like high blood pressure and type 2 diabetes, known risk factors for kidney disease.

So, while obesity isn't a direct cause, it creates conditions that can lead to kidney disease.

Weight Loss's Role in Kidney Health

Losing weight alone may not directly improve kidney function. Still, it can help manage conditions like diabetes and high blood pressure, which contribute significantly to kidney disease. Managing these conditions can contribute to protecting the kidneys, and over time, there may be some recovery in kidney function.

Weight loss that improves overall health and metabolism may indirectly benefit kidney function. However, sustained weight loss and long-term lifestyle changes are necessary to see these benefits.

It's important to note that the relationship between weight loss and kidney function improvement is complex and involves multiple factors.

Weight Changes in Advanced Kidney Disease

Weight shifts are common in people with advanced kidney disease. As kidney function declines, substances normally filtered by the kidneys, such as potassium, sodium, and phosphorus, can accumulate and become toxic.

Changes in electrolyte levels and fluid shifts can lead to weight gain. Fluid gains contribute to weight gain and are most common in the later stages of kidney or end-stage renal disease.

Weight Management Struggles in Kidney Disease

While fluid weight gain is common in the later stages of kidney disease, weight loss can also be a concern. Individuals with kidney disease may be advised to follow specific diets, limiting foods high in substances like potassium and sodium.

These dietary restrictions and recommendations to limit fluid intake can make it challenging to consume enough calories, potentially leading to weight loss.

Prevention For Obesity-Related Kidney Diseases

Given the substantial risks associated with obesity and kidney health, taking proactive measures is important. Here are some ways to keep your kidneys healthy:

  • Limit salt intake: Reduce your daily salt intake to less than 2,300 milligrams (about a teaspoon) to lower the risk of high blood pressure and heart disease.
  • Drink alcohol in moderation: Limit alcoholic drinks to one per day for women and up to two per day for men, as excessive alcohol consumption can harm the liver and increase the risk of addiction.
  • Avoid or stop smoking: Eliminate smoking entirely to decrease the risk of lung cancer, heart disease, and respiratory issues.
  • Eat more fruits and vegetables: Aim for at least five servings daily to provide your body with essential vitamins, minerals, and fiber. This also helps lower the risks of developing serious health conditions.
  • Drink sufficient water daily: Drink six to eight ounces of glasses of water daily to maintain proper bodily functions, including digestion and temperature regulation.
  • Engage in regular exercise: Have at least 150 minutes of moderate-intensity aerobic activity or aim for 75 minutes of vigorous-intensity aerobic activity each week, combined with muscle-strengthening activities on two or more days.
  • Take your medications as prescribed: ​​​​To successfully manage chronic diseases, take your prescription medications regularly and as advised by your healthcare practitioner.
  • Monitor your cholesterol, blood pressure, and sugar levels: Schedule routine check-ups to keep track of your blood pressure and sugar levels, and cholesterol to prevent heart disease, hypertension, and diabetes.
  • Limit using anti-inflammatory drugs or pain relievers: Limit over-the-counter anti-inflammatory drugs or pain relievers to the recommended dosage and duration to prevent potential side effects such as gastrointestinal issues.

The Bottom Line

Kidney disease and weight gain are linked as obesity significantly elevates the risk of kidney disease, particularly CKD. Obesity contributes to kidney disease through various pathways, including developing conditions like type 2 diabetes, high blood pressure, and fluid retention.

With more and more people becoming overweight, it's vital to keep an eye on what are the causes of abnormal weight gain and learn how to manage them to prevent kidney disease. Detecting kidney disease early is crucial, as its symptoms may not manifest until it has advanced.

To mitigate this risk, it's important to maintain a healthy weight with a balanced diet, consistent exercise, and lifestyle changes. This will safeguard your kidneys and keep them operating at their peak performance.

FAQs About Weight Gain and Kidney Disease

Can you live without a kidney?

You can't live without kidneys, but living with just one is possible. Some are born with only one or lose one for various reasons. The remaining kidney can compensate and lead to a normal life with a healthy lifestyle and regular check-ups.

Is high fat bad for the kidneys?

Consuming excessive fat, especially saturated and trans fats, can harm your heart, blood vessels, and kidneys. Those with kidney problems should exercise caution and choose healthier monounsaturated and polyunsaturated fats in oils like canola or corn.

Are thyroid and kidney disease and weight gain related?

Yes, thyroid and kidney diseases can indirectly relate to weight gain. Hypothyroidism (an underactive thyroid) is linked to weight gain because producing low thyroid hormones, which control metabolism in the body, slows down metabolism. Kidney disease can result in weight gain from fluid retention. Both conditions, when untreated, can contribute to weight-related issues.

Can kidney disease make you lose weight?

In the context of kidney disease and weight gain, early-stage kidney disease often leads to sudden weight gain due to fluid retention. As the disease advances, weight loss occurs from reduced appetite, nutrient loss, and metabolic shifts. Advanced kidney disease amplifies these effects, harming overall health.

Why is it important to know the link between kidney disease and weight gain?

Understanding the link between kidney disease and weight gain is crucial because obesity can cause or exacerbate kidney damage due to increased pressure on the kidneys and metabolic changes. Recognizing this link allows early intervention for at-risk obese individuals, protecting their kidney health and well-being.

Illustration of a healthcare provider asking questions on a smart phone.
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A personalized GLP-1 medication program delivered to you via our partner Korb Health
Illustration of a healthcare provider asking questions on a smart phone.
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  • Prescription medications and supplies shipped to your door