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Sodium, fluid and chronic kidney disease

When you have chronic kidney disease (CKD), one of the treatments is your diet. Your doctor or dietitian may tell you to reduce the amount of sodium and fluid you consume. In addition, you may also be told to restrict your intake of protein, potassium and phosphorous. The goal of the kidney diet is to lessen the strain on your kidneys, while ensuring that you get the nutrients you need for good health.

When kidneys are not able to function at full capacity, they may have a hard time eliminating excess fluid and wastes. The build up of fluid in the body can be observable in puffy eyes, swollen ankles, difficulty breathing, but sometimes there are harmful effects you cannot see, including elevated blood pressure and an accumulation of fluid around the heart or lungs. Excess fluid in someone with CKD can even lead to congestive heart failure. If you have high blood pressure, it can lead to further kidney damage. Too much sodium in your body can leads to higher blood pressure. Restricting the amount of sodium you consume may help reduce these issues.

My doctor recommends a low-sodium diet – now what do I do?

If your doctor has told you that you need to limit the sodium in your diet, you can create a healthy eating plan using other flavoring alternatives to add flavor to your foods.

Start by setting up a meeting with a renal dietitian to find out which foods and beverages would be best to limit or avoid and which ones can still be enjoyed. When you work with a dietitian, your kidney-friendly diet is tailored to your individual needs. And you may find that over time, your kidney diet will evolve. Here are some tips that are designed to help you meet the challenges of sticking to a healthy, low-sodium eating plan:

  • Know how much sodium you should eat daily. Your dietitian can give you guidelines. Keep a journal of the foods you eat so you can track the amount of salt you’re consuming.
  • Always read nutrition labels when grocery shopping, and be on the watch for salt (sodium, sodium benzoate, sodium nitrite, sodium sorbate). If you see salt in the first five ingredients, the food is probably not appropriate for your low-salt diet. Often, different brands of a particular type of food will contain widely varying amounts of salt, so compare brands and stick to the ones with the lowest sodium content.
  • Limit the amounts of processed and canned foods you eat. Eat more fresh meats, fish, poultry, fruits and veggies. If you buy frozen foods, choose those that do not have added ingredients.
  • Remove the salt shaker from your dining table, or instead of salt, fill the shaker with another herb or seasoning that doesn’t contain sodium. 
  • Be aware that low-sodium foods and salt substitutes are often high in potassium, so they may not be right for your kidney-friendly diet plan.
  • Rinse high-sodium canned foods, such as tuna, before eating to help remove some of the salt.
  • When cooking at home, use herbs, spices, garlic or lemon to flavor your foods rather than salt. Buy yourself a low-salt cookbook and experiment to find recipes that you and your family like.
  • When eating out, let your server know that you need to avoid salty foods. Ask that your meal be prepared without salt or MSG. Gravies, sauces and salad dressings can be especially high in salt, so avoid them or ask to have them served on the side so you can choose the amount you add to your meal.

As you begin eating less salt, you will find that your desire for it will diminish with time. You may find that you prefer the taste of natural seasonings, which allow food’s true flavor to come through.

Some high-sodium foods

Limit or avoid these foods that are high in sodium:

  • Salted butter, buttermilk and peanut butter
  • Some cereals 
  • Sports drinks
  • Vegetable juices
  • Fast foods
  • Baking powder and baking soda
  • Canned fish: tuna, salmon, sardines
  • Most cheese and cheese spreads
  • Salty snacks, including chips, pretzels, nuts, popcorn, crackers
  • Quick-cooking rice and instant noodles, prepared mixes for rice, scalloped potatoes,  macaroni and cheese
  • Smoked or cured meats: ham, hot dogs, bacon, bologna, sausage, pastrami, corned beef, lunch meats
  • Certain frozen dinners, pot pies and pizzas
  • Regular canned vegetables
  • Pickled foods: relish, olives, pickles, herring, sauerkraut 
  • Regular canned and instant soups
  • Condiments and flavorings such as ketchup, mustard, barbecue sauce, soy sauce, steak sauce, teriyaki sauce, salad dressing, garlic salt, onion salt, seasoned salts, lemon pepper, bouillon cubes, meat tenderizer and monosodium glutamate (MSG)

Controlling fluid intake

For people with end stage renal disease and are on dialysis, your health care practitioner may recommend that you limit the amount of fluids you drink each day. Dialysis gets rid of excess fluid, but it is not the same as healthy kidneys that work 24 hours per day, so fluid can build up between treatments. Also, a dialysis treatment can only remove a certain amount of fluid. Sticking to the recommended amount of fluids you drink can help:

  • Keep you feeling comfortable between dialysis treatments
  • Prevent adverse effects, such as muscle cramping and a drop in blood pressure, that occur when a greater-than-normal amount of fluid is removed during a single dialysis treatment

Your dietitian will help you determine exactly what your fluid restriction should be, taking into consideration your urine output, the appearance of swelling in your body and the amount of weight you gain between dialysis treatments. If you experience a sudden weight gain, it may signal that you are consuming too much fluid, and you should contact your doctor right away.

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