For a renal diet it is important to manage protein intake from sources like chicken, beans, fish and eggs, as excessive consumption can overload the kidneys. This can impair kidney function and lead to symptoms such as back pain, tiredness, pain when urinating or frequent urge to urinate.
Patients who are on a renal diet should also be cautious with their potassium intake from foods like cheese, nuts, coconut and dried fruit. Excess potassium intake can lead to the accumulation of this mineral in the body, which can also overload the kidneys and potentially cause heart problems.
However, before starting a renal diet, it is essential to consult a registered dietitian who will assess your health status, your kidney problem and your own individual health needs.
Goals of the renal diet
The renal diet for kidney failure varies according to the patient's stage of kidney disease. The goals of this diet are to maintain optimal weight, preserve kidney function and avoid complications such as fluid retention, tiredness, anemia and high blood pressure.
The renal diet can vary depending on whether or not the person is undergoing hemodialysis, which is a treatment for severe kidney disease that involves the filtration of the blood to eliminate excess toxins, minerals and fluids from the body. Patients on conservative treatment (that is, the kidney disease is treated through other measures like medication) require less calories, protein, potassium and phosphorus.
Sample meal plan
The following table contains an example of a 3-day menu with general guidelines for kidney failure:
In addition to diet, patients with kidney disease are also advised to exercise to avoid excess weight gain, control high blood pressure and improve kidney function.
Conservative renal diet
The conservative renal diet is recommended for people with kidney failure who have altered kidney function but are not undergoing hemodialysis. In this case, it is important to maintain a balanced intake of the following nutrients:
- Calories: the diet should contain between 25 and 35 calories / kg of body weight per day. A person weighing 60 kg should consume between 1500 and 2100 calories a day, for example, depending on their health status, weight, age and gender;
- Protein: in this case, protein intake should be reduced to between 0.6 and 0.8 g per kg of body weight per day. A person weighing 60 kg should eat 36 to 48 g of protein a day, which is equivalent to 1 boiled egg and 100 g of chicken breast, for example;
- Sodium: as high blood pressure is one of the causes or consequences of kidney failure, it is important to reduce sodium intake, with a recommended intake of up to 2 g of sodium, which corresponds to 5 g of salt per day;
- Fluids: people undergoing conservative treatment generally don't need to reduce the volume of fluid intake. However, depending on the severity of the disease, the nephrologist or nutritionist may recommend reducing fluids, however, which should be assessed on an individual basis;
- Potassium: the consumption of potassium, present in foods such as bananas, dried fruit and legumes, should only be reduced when indicated by a doctor or nutritionist. For this reason, in some cases it may be necessary to limit the intake of this mineral to 1 to 3g a day.
In addition, if blood phosphorus levels are high, the doctor or nutritionist may restrict phosphorus intake to a maximum of 1g per day.
It's important to remember that the renal diet should be adjusted according to the degree of kidney failure, the state of health, age and gender of each person, which is why it's recommended to consult a nutritionist before starting the diet.
Renal diet for hemodialysis
The renal diet for hemodialysis is important to prevent overloading the kidneys, swelling, weight loss and loss of muscle mass, all which can happen during hemodialysis sessions. Therefore, the nutritional recommendations for people on hemodialysis are:
- Energy: the energy recommendation ranges from 30 to 40 calories / Kg of body weight per day. A person weighing 60 kg needs to consume between 1800 and 2400 calories a day, for example;
- Protein: the amount of protein intake is increased, as a lot of this nutrient is lost during hemodialysis sessions, and an intake of 1.3 to 2g of protein per kg of body weight per day is recommended;
- Sodium: controlling sodium intake is important to prevent thirst, excess body fluid and high blood pressure. We recommend consuming 1.8 to 2.3 g of sodium per day, which corresponds to a maximum of 5.7 g of salt per day;
- Fluids: fluid intake must be well-controlled to avoid swelling, shortness of breath and high blood pressure, and is recommended at 500 ml + the volume of urine in 24 hours a day. For example, if the volume of urine in 24 hours is 300 ml, then the intake should be 500 ml + 300 ml, totaling 800 ml of fluids per day, which includes pure water and the water used to prepare coffee, soups and teas;
- Phosphorus: during hemodialysis it is important to closely manage the intake of foods rich in phosphorus, such as dairy products, whole grains, dried fruit and legumes, because during this phase the body generally has high concentrations of this mineral.The recommended intake of phosphorus is between 0.8 and 1.2 g per day;
- Potassium: depending on the levels of potassium in the blood, it is recommended to reduce potassium intake to up to 2.5 g per day.
To reduce your intake of potassium from food, you can also eat fruits and vegetables peeled and cooked, as cooking in water reduces the content of this mineral in food.
Kidney stone diet
The kidney stone diet helps to manage the size of kidney stones and prevent symptoms such as painful urination, back pain and fever. The goals of kidney stone diet are to prioritize foods with great amounts of calcium and water, as these help to prevent the formation of stones and promote their elimination.
Foods that you should include in the kidney stone diet include:
- Dairy products, such as yogurt, milk and cheese;
- Fresh fruit, such as oranges, apples, pears, strawberries, oranges and lemons;
- Fresh vegetables such as tomatoes, lettuce, cucumbers, carrots, zucchini and chayote;
- Water: drink 2.5 liters of water a day;
- Legumes, such as beans, lentils, chickpeas or soybeans. (Legumes contain a high oxalate content, so it is recommended to soak these foods in water before preparing them.)
It is also important to avoid foods rich in calcium oxalate, a compound found in foods such as legumes, cereals and some fruits, which in excess can cause kidney stones. Patient should also avoid high-sodium foods, as this mineral increases the elimination of calcium through the urine. It is also advisable to pay attention to the amount of protein consumed during the day, as this can also promote kidney stone formation. See ARTICLE NOT FOUND ON EN: more details on the kidney stone diet.
Kidney infection diet
For cases of kidney infections, it is recommended to prioritize healthy and natural foods, such as fresh fruit and vegetables, whole grains, dairy products, legumes and lean proteins. Patient should also increase fluid intake, which will help increase urine volume and promote the elimination of the bacteria causing the infection.
Cranberries can also be included in the diet, as they are rich in polyphenols, making it difficult for bacteria that cause infection to adhere to the urinary tract. This can help prevent worsening and fight active infections.
It is important to avoid consuming certain foods that can alter the intestinal flora and cause bladder irritation, such as:
- Refined cereals, such as white rice, white wheat flour and white pasta
- Sweets, such as sugar, ice cream, cakes or chocolate
- Caffeine, such as coffee, green tea, black tea and mate
- Processed meats, such as sausage, bacon, bratwurst and salami
It is also recommended to avoid drinking alcoholic beverages such as beer, wine or sparkling wine, as they can irritate the kidneys and can worsen kidney infections.
