7 Foods That Can Negatively Affect Your Kidneys and What to Eat Instead

Your kidneys may be small, but they do some of the body’s most important work. They filter waste and excess fluid from your blood, help regulate blood pressure, and maintain the right balance of minerals and electrolytes.

What you eat can play an important role in kidney health, particularly if you have chronic kidney disease (CKD), diabetes, high blood pressure, or another condition that increases your risk of kidney problems.

So, what foods are bad for your kidneys? There isn’t one universal list. For most people with healthy kidneys, individual foods rarely need to be completely avoided. However, regularly eating foods high in sodium, added sugar, and certain other nutrients can contribute to health problems that place additional strain on the kidneys.

For people with kidney disease, dietary needs can be more specific. Depending on your kidney function and lab results, your healthcare provider may recommend limiting sodium, phosphorus, potassium, protein, or fluids.

Here are seven foods that may negatively affect your kidneys — and some kidney-friendly alternatives to consider.

1. Processed Meats

Bacon, sausage, hot dogs, deli meats, and other processed meats can contain large amounts of sodium. Too much sodium can contribute to high blood pressure and fluid retention, both of which can be particularly concerning for people with kidney disease.

Processed meats may also contain phosphorus additives, which can be an additional consideration for some people with CKD.

Try instead: Choose fresh, minimally processed proteins such as chicken, turkey, fish, or eggs. Look for products without added phosphorus and choose lower-sodium options when available.

2. Salty Snacks

Chips, crackers, pretzels, and other packaged snacks can deliver a surprising amount of sodium in a relatively small serving.

A high-sodium diet can raise blood pressure, and high blood pressure is both a major cause and complication of chronic kidney disease. Reducing sodium is therefore an important part of many kidney-friendly diets.

Try instead: Reach for fresh fruit, unsalted popcorn, vegetables, or other minimally processed snacks. When buying packaged foods, compare nutrition labels and choose options with less sodium.

3. Sugary Drinks

Soda, sweetened teas, energy drinks, and other sugar-sweetened beverages can contribute to excess calorie intake, weight gain, and type 2 diabetes. Diabetes is one of the leading causes of chronic kidney disease.

Some dark-colored sodas may also contain phosphorus additives, which people with advanced kidney disease may be advised to limit.

Try instead: Make water your primary beverage. Unsweetened sparkling water or water flavored with lemon, lime, cucumber, or berries can add variety without a large amount of added sugar.

4. Highly Processed and Fast Foods

Fast food, frozen meals, boxed dinners, and other highly processed foods can be convenient, but they are often high in sodium, saturated fat, and added sugars.

Eating these foods frequently can make it harder to maintain healthy blood pressure, blood sugar and weight — all factors that can affect your kidneys over time.

For people following a chronic kidney disease diet, processed foods can also make it difficult to control sodium, potassium, and phosphorus intake.

Try instead: Build meals around fresh or minimally processed ingredients when possible. A simple meal of lean protein, vegetables and whole grains can give you greater control over what you’re eating.

5. Foods High in Added Sugar

Cookies, pastries, candy, sweetened cereals and other foods high in added sugar aren’t directly “toxic” to your kidneys. The concern is what can happen when they become a regular part of your diet.

Eating too much added sugar can contribute to weight gain, insulin resistance, and type 2 diabetes — all of which can increase your risk of developing kidney disease.

Try instead: Satisfy your sweet tooth with fresh fruit or choose foods with little or no added sugar. Checking the “Added Sugars” line on nutrition labels can help you compare products.

6. Foods With Phosphorus Additives

Phosphorus is a mineral your body needs. Healthy kidneys normally remove excess phosphorus from the blood, but damaged kidneys may have difficulty doing so.

As kidney disease progresses, some patients may need to limit phosphorus. Processed foods, packaged baked goods, processed meats, and some beverages can contain added phosphorus that is readily absorbed by the body.

Try instead: Choose fresh foods more often and check ingredient lists for words containing “phos,” such as phosphoric acid or phosphate. If you have CKD, ask your healthcare provider or dietitian how much phosphorus is appropriate for you.

7. High-Potassium Foods — for Some People With Kidney Disease

Potassium is essential for healthy muscles, nerves and heart function, and potassium-rich foods are generally part of a healthy diet. But when kidney function declines, the kidneys may have difficulty removing excess potassium from the blood.

That means foods such as bananas, oranges, potatoes, tomatoes and avocados may need to be limited by some people with kidney disease.

However, you shouldn’t automatically eliminate potassium-rich foods simply because you have CKD. Potassium needs vary significantly based on kidney function, medications, and blood test results.

Try instead: If your healthcare provider has recommended limiting potassium, ask about lower-potassium choices such as apples, berries, grapes, cabbage, cauliflower, and bell peppers.

What Are the Best Foods for Healthy Kidneys?

If you don’t have kidney disease, protecting your kidneys generally doesn’t require following a restrictive “renal diet.” Instead, focus on eating patterns that support healthy blood pressure, blood sugar, and cardiovascular health.

A balanced diet may include fruits and vegetables, whole grains, lean proteins and healthy fats while limiting excessive sodium, added sugars and highly processed foods.

Other ways to help protect your kidneys naturally include staying physically active, maintaining a healthy weight, managing blood pressure and blood sugar, staying appropriately hydrated and avoiding excessive use of medications that can affect kidney function.

What Foods Should You Avoid If You Have Kidney Disease?

There is no single list of foods to avoid if you have kidney disease that applies to everyone.

A renal diet may need to control sodium, potassium, phosphorus, protein, or fluids, depending on the type and stage of kidney disease and your individual health needs. In some cases, unnecessarily restricting these nutrients can make it harder to get the nutrition your body needs.

Instead of following a generic kidney-friendly meal plan you find online, work with your healthcare provider or a registered dietitian to determine what’s appropriate for you.

What Are the Signs Your Kidneys Are Unhealthy?

Early kidney disease often causes few or no noticeable symptoms. That’s one reason screening can be important for people with risk factors such as diabetes, high blood pressure, heart disease, or a family history of kidney disease.

As kidney disease progresses, symptoms can include swelling in the legs or ankles, changes in urination, fatigue, nausea, loss of appetite, muscle cramps, or difficulty concentrating. These symptoms can also have many other causes, so experiencing one doesn’t necessarily mean you have kidney disease.

Blood and urine tests are typically needed to determine how well your kidneys are functioning.

Protecting Your Kidney Health Starts With the Bigger Picture

When it comes to kidney disease prevention, don’t focus too heavily on a single “good” or “bad” food. Your overall eating pattern — along with your blood pressure, blood sugar, activity level, and other health factors — matters much more.

And if you already have kidney disease, your nutritional needs may be very different from those of someone with healthy kidneys.

A healthcare provider can help assess your kidney function, identify your individual risk factors, and determine whether changes to your diet could help protect your kidneys.

Have questions about your kidney health? Talk to a Revere Health nephrologist today to get personalized guidance based on your health, kidney function, and nutritional needs.