When scar tissue forms in some of the kidneys’ tiny filters — a condition known as focal segmental glomerulosclerosis (FSGS) — the kidneys have to work harder to remove waste and balance fluids in the body. Your food choices can also impact how hard your kidneys have to work.
“For someone with FSGS, diet can affect blood pressure control, protein loss in the urine (proteinuria), and the rate of kidney disease progression,” says Jen Hernandez, RDN, a board-certified renal dietitian based in Fort Lauderdale, Florida, and the author of Plant-Powered Kidney Nutrition
Along with following the treatments your nephrologist prescribes, a FSGS-friendly diet often involves limiting foods high in sodium, which can worsen fluid retention and raise blood pressure. It’s also important to cut back on phosphorus and potassium intake, as these minerals can accumulate too much in the blood when the kidneys aren’t working well to remove them.
Here are some foods that experts commonly recommend limiting or avoiding if you have FSGS. But bear in mind that nutrition needs can vary based on factors like disease severity, treatments, and other health conditions, making it a good idea to check with your healthcare team or a registered dietitian familiar with kidney disease before making dietary changes.
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Processed Meats
Processed meats like hot dogs, sausage, and deli meat contain high amounts of sodium. Three ounces of deli turkey, which is four to six thin slices, can have up to 800 milligrams (mg) of sodium, says Melanie Betz, RD, the Chicago-based founder and CEO of the Kidney Dietitian. That’s nearly half the daily sodium limit for people with chronic kidney disease (CKD), including FSGS, who are often advised to stay under 2,000 mg of sodium per day, though individual limits can vary based on blood pressure, kidney function, and medications. And if you’re making a sandwich, that’s before you factor in the sodium content in bread and condiments.
In addition to sodium, processed meat often contains potassium and phosphorus additives, and the body absorbs these chemically added minerals more easily than the naturally occurring forms found in whole foods. In people with FSGS, the kidneys may have a hard time removing these minerals from the body, which can lead to an unhealthy accumulation in the blood. High potassium levels can cause irregular heart rhythms and muscle weakness. Excess phosphorus in the blood may weaken the bones and increase the risk of bone fracture.
Both sodium and these mineral additives drive up blood pressure and can accelerate kidney disease progression, says Hernandez. To protect your kidneys, check nutrition labels and look for products with 140 mg of sodium or less per serving, which the U.S. Food and Drug Administration considers low sodium, she says. Avoid products with any ingredient containing “phos,” like dicalcium phosphate, which indicates that phosphorus has been chemically added to the food, Hernandez adds.
For a more kidney‑friendly alternative, Betz suggests making sandwiches with roasted vegetables and hummus, or using slices of baked chicken you’ve prepared at home. Roasting a turkey breast yourself is another good option. Also look for low-sodium bread with 140 mg or less of sodium per serving, or make a lettuce wrap instead. Fish and legumes are also healthier swaps for processed meats, says Hernandez.
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Salty Snacks
There’s a reason why salty snacks like chips and pretzels are some of the first foods that kidney dietitians recommend people with FSGS avoid or limit. Salty snacks can contain anywhere from about 150 mg to about 300 mg or more of sodium per serving, and because serving sizes are usually small, it’s easy to eat far more than you realize in one sitting, says Hernandez. Research suggests that separate from its effect on blood pressure, high salt intake may contribute to kidney inflammation, she notes.
Not only do salty snacks add sodium, they also tend to have added potassium or phosphorus in them, says Betz. As with processed meats, these minerals can accumulate in the body if the kidneys aren’t working well. On top of that, salty snacks don’t add much nutrition, like fiber, vitamins, minerals, or antioxidants, Betz says.
When you're craving something crunchy, both dietitians recommend reaching for fresh fruit, raw vegetables, unsalted nuts, or homemade roasted chickpeas instead of salty snacks.
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Red Meat
Protein helps support muscle health and many of the body’s functions. But in people with FSGS, red meat such as beef, pork, and lamb can put extra pressure on the kidneys’ already stressed filters, says Hernandez.
Eating too much red meat can lead to high potassium and phosphorus levels in the body, says Betz. While there’s no specific red meat intake limit for people with FSGS, guidelines recommend that adults with CKD aim for about 0.8 grams (g) of protein per kilogram of body weight per day. For someone who weighs 150 pounds, that works out to roughly 55 g of protein per day. One palm-sized serving of raw beef flank steak contains about 23 g of protein.
Compared with plant-based protein sources, red meat produces more of a type of waste product called uremic toxins. When your kidneys aren’t working well, as in people with FSGS, these toxins can accumulate in the blood and cause various symptoms, including fatigue, nausea, and loss of appetite.
Saturated fat in fatty cuts of red meat is another concern, especially for people with FSGS who develop nephrotic syndrome, a complication of FSGS. With nephrotic syndrome, large amounts of protein leak into the urine, and in response, the liver produces more cholesterol, leading to high cholesterol levels in the blood and increasing the risk of heart disease.
Because protein needs and the recommended source of protein can vary depending on your kidney function and disease stage, consider working with a renal dietitian to map out a personalized plan. Fortunately, whole foods annd plant-based proteins such as beans, lentils, tofu, edamame, nuts, and seeds are all kidney-friendlier choices, say Betz and Hernandez.
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Canned Soups
Another major source of sodium is canned soup; a single serving could contain anywhere from 800 to 1,500 mg of sodium, says Hernandez. That’s nearly an entire day’s worth of sodium for someone with CKD. Plus, phosphorus and potassium additives are commonly used in these soups to improve shelf life and flavor, Betz says.
Lower-sodium versions often use salt substitutes that can also be problematic, says Betz. Salt substitutes replace sodium with potassium chloride, a mineral that can lead to high potassium levels in the blood. Check the ingredients and limit products that contain potassium chloride, she says.
Better yet, making soup at home gives you the most control over what ends up in your bowl. Betz suggests starting with unsalted broth and building flavor with herbs, spices, garlic, and onions. If your recipe calls for meat, boiling it first and discarding the water can remove a significant amount of phosphorus. For a healthier option, replace the meat with beans. If you use canned beans, choose no-salt-added beans and rinse them before using.
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Store-Bought Salad Dressing
The dressing on your greens can be a significant source of sodium that may take away from the health benefits of the salad, says Betz. Most commercial salad dressings rely on sodium-containing ingredients and preservatives to enhance flavor and extend shelf life.
Just 2 tablespoons of some bottled Italian dressings contain nearly 300 mg of sodium, and many people use more than that without realizing it. That’s already a noticeable portion of the recommended daily sodium allowance for people with CKD. Salty toppings like cheese and croutons can push the sodium content even higher.
Try making your own salad dressing at home with a heart-healthy oil like olive oil, whisked together with balsamic vinegar or fresh lemon juice, suggests Betz. This often takes just a few minutes and gives you control over the ingredients while still adding flavor.
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Sweetened Beverages
Fructose is a type of sugar commonly used to sweeten sodas, fruit punch, iced tea, and other sugary beverages, and it's been linked to a higher risk of CKD, says Hernandez.
Plus, dark colas — both regular and diet versions — are notorious sources of added phosphorus, says Betz, and this additive can even appear in some flavored waters.
For a swap, stick to unsweetened flavored sparkling water, unsweetened herbal teas, or just plain water to stay hydrated without excess sugar or hidden additives, she says.
Resources We Trust
- Cleveland Clinic: Hyperkalemia (High Potassium)
- Mayo Clinic: 5 Nutrition Tips for Chronic Kidney Disease
- National Kidney Foundation: How Much Sodium Is Safe for Kidney Patients?
- American Kidney Fund: Kidney-Friendly Eating Plan
- National Kidney Foundation: Phosphorus and Your CKD Diet
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Reyna Franco, RDN
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