25. Diet in Chronic Kidney Disease
Diet in Chronic Kidney Disease
The major role of kidneys is to remove waste products and purify blood.
Besides this, the kidney plays an important role in removing extra water,
minerals and chemicals; and regulates water and minerals like sodium,
potassium, calcium, phosphorus and bicarbonate in the body.
In patients suffering from chronic kidney disease, (CKD) regulation of
fluid and electrolytes may be deranged. Because of this reason even
normal intake of water, common salt or potassium can cause serious
disturbances in fluid and electrolytes balance.
To reduce the burden on the kidney with impaired function and to avoid
disturbances in fluid and electrolytes balance, patients with chronic
kidney disease should modify their diet as per the guidance of the doctor
and the dietician. There is no fixed diet for CKD patients. Each patient
is given different dietary advice depending on clinical status, the stage
of kidney failure and other medical problems. Dietary advice needs
alteration even for the same patient at different times.
The goals of dietary therapy in CKD patients are:
1. To slow down the progression of chronic kidney disease and to
postpone the need of dialysis.
2. To reduce toxic effects of excess urea in the blood.
3. To maintain optimal nutritional status and prevent the loss of lean
4. To reduce the risk of fluid and electrolytes disturbances.
5. To reduce the risk of cardio vascular disease.
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General principles of dietary therapy in CKD patients are
- Restrict protein intake to 0.8 gm/kg of body weight/day.
- Supply adequate carbohydrate to provide energy.
- Supply moderate amount of fats. Cutt down intake of butter, ghee
- Limit the intake of fluid and water in case of swelling.
- Restrict the amount of sodium, potassium and phosphorus in diet.
- Supply vitamins and trace elements in adequate amount. High fiber
Details of selection and modification in diet of patients with CKD
are as follows:
1. High Calorie Intake
The body needs calories for daily activities and to maintain temperature,
growth and adequate body weight. Calories are supplied chiefly by
carbohydrates and fats. Usual requirement of calories in CKD patients
is 35 - 40 kcals/kg body weight per day. If caloric intake is inadequate,
protein is used to provide calories. This break down of protein can
lead to harmful effects such as malnutrition and greater production of
waste products. So it is very essential to provide adequate amount of
calories to CKD patients. It’s important to calculate the calories
requirement to patient’s ideal body weight and not current weight. The
weight may be either low or high especially so in patient’s pre-existing
malnutrition or in diabetics with CKD
Carbohydrates are the primary source of calories for the body.
Carbohydrates are found in wheat, cereals, rice, potatoes, fruits and
vegetables, sugar, honey, cookies, cakes, sweets and drinks. Diabetics
and obese patients need to limit the amount of carbohydrates. It's best
CHP. 25. Diet in Chronic Kidney Disease 197.
to use complete carbohydrates from cereals like whole wheat,
unpolished rise and millets like johar, bajra, ragi, nachni which would
also give fibres. These should form large part of carbohydrates or all
other simple sugar containing substances should form not more 20% of
are important source of calories for the body and provide two
times more calories than carbohydrates or proteins. Unsaturated or
"good" fats like olive oil, peanut oil, canola oil, safflower oil, sunflower
oil, fish and nuts are better than saturated or "bad" fats such as red
meat, poultry, whole milk, butter, ghee, cheese, coconut and lard. Reduce
intake of saturated fats and cholesterol as they can cause heart disease
and kidney damage.
Among the unsaturated fats it is important to pay attention to proportion
of monounsaturated and polyunsaturated fats. Excessive amounts of
omega-6 polyunsaturated fatty acids (PUFA) and a very high omega-
6/omega-3 ratio is harmful while low omega-6/omega-3 ratio exerts
beneficial effects. Mixtures of vegetable oil rather than single oil usage
will achieve the purpose. Trans fats containing substances like Vanaspati/
Dalda Ghee, potato crisps, doughnuts, commercially prepared cookies
and cakes are potentially harmful and should be avoided.
2. Restrict Protein Intake
Protein is essential for the repair and maintenance of body tissues. It
also helps in healing of wounds and fighting against infection.
Protein restriction reduces the rate of decline in kidney function and
thus delays the need for dialysis and kidney transplantation. But avoid
undue protein restriction. Poor appetite is common in CKD patients.
Poor appetite and strict protein restriction together can lead to poor
nutrition, weight loss, lack of energy and reduction in body resistance;
which increases the risk of death.
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In India, people consume mostly vegetable diet. Even those who eat
non-vegetarian food don't do so on regular daily basis. The diet consume
most of times both in socio-economic or better of family still fall short
of protein intake advocated Indian Council of Medical Research
(ICMR) which is 1gm per kg body weight. Hence, thought restriction
of protein to 0.8 gm/kg is advocated for advancing stages of CKD, it is
only the marginally. The emphasis should be improving the quality of
protein consumed. Attention must be paid to eating protein of high
biological value (0.4 to 0.6 gms/kg) containing milk products curd,
paneer, refined soyabeen powder, soya granule, soya chunks, egg white
etc. and for non-vegetarian egg white on daily basis and small quality of
3. Fluid Intake
Why must patients of CKD take precautions in fluid intake?
Kidneys play a major role in maintaining proper amount of water in the
body by removing the excess fluid as urine. In patients with CKD, as
the kidney functions worsen, the volume of urine usually decreases.
Reduced urine output leads to retention and excess fluid in the body
causing puffiness of the face, swelling of the legs and hands and high
blood pressure. Accumulation of fluid in lungs causes shortness of breath.
If this is not controlled, it can be life threatening.
What are the clues of excess water in the body?
Excess water in the body is called fluid overload. Swelling, ascites
(accumulation of fluid in the abdominal cavity), shortness of breath, and
weight gain in a short period are the clues which indicates fluid overload.
What precautions patients of CKD must take to control fluid
To avoid fluid overload or deficit, volume of fluid should be taken as
per the recommendation of the doctor. Volume of fluid permitted may
CHP. 25. Diet in Chronic Kidney Disease 199.
vary for each CKD patient and is calculated on the basis of urine output
and fluid status of each patient.
How much fluid is a chronic kidney disease patient advised
- In patients without swelling and with adequate urine output,
unrestricted water and fluid intake is permitted. But patients with
chronic kidney disease should take large amounts of fluid to protect
kidney is a misconception.
- Patients with swelling and reduced urine output are instructed to
restrict fluid intake. To reduce swelling, fluid permitted in 24hrs should
be less than the volume of urine in a day.
- To avoid fluid overload or deficit, volume of fluid usually permitted
in a day = urine volume of previous day plus 500ml. Additional
500ml of fluid approximately makes up for the loss of fluid through
perspiration and breathing.
Why must patient of CKD weigh themselves daily and maintain
To monitor fluid volume in the body and to detect fluid gain or loss at
the earliest, the patients should weigh themselves daily and record it.
The body weight remains constant when the instructions of fluid intake
are followed strictly. Sudden weight gain indicates fluid overload due to
increase in fluid intake. Weight gain warns the patients about the need
of more meticulous fluid restriction. Weight loss usually occurs as a
combined effect of restriction of fluid and response to diuretics.
Useful Tips to Reduce Fluid Intake :
To restrict fluid intake is difficult, but these tips will help you:
1. Weigh yourself at a fixed time every day and adjust fluid intake
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2. The doctor advises you on how much fluid consumption is permitted
in a day. Accordingly calculate properly and drink measured
volume of fluid every day. Remember fluid intake includes not only
water but also tea, coffee, milk, curd, buttermilk, juice, ice-cream,
cold drinks, soup, thin dal etc. While calculating fluid intake you
must also calculate the hidden fluids in your food. Beware foods
such as watermelon, grapes, lettuce, tomatoes, celery, gravy, gelatin,
frozen treats like popsicles etc. as they have high water content.
3. Reduce salty, spicy and fried food in your diet as they increase
thirst, leading to greater consumption of fluids.
4. Drink only when you are thirsty. Do not drink as a habit or because
everyone is drinking.
5. When you are thirsty take a small amount of water or try ice. Take
a small ice cube and suck it. Ice stays longer in the mouth than
liquid, so it is more satisfying than the same amount of water. Do
not forget to account for ice as consumed fluid. For easy calculation,
freeze the allotted amount of water into an ice tray.
6. To take care of dryness of mouth, one can gargle with water without
drinking it. Dryness of mouth can be reduced by chewing gums,
sucking hard candy, lemon wedge or mints and the use of
mouthwash to moisten mouth.
7. Always use small size cup and glass for your beverages to limit
8. Take medicines after meals when you are taking water to avoid
extra water consumption for medicine.
9. A patient must keep himself busy with work. A patient who has
little to occupy himself feels the desire, to drink water more often.
10. High blood sugar in diabetic patients can increase thirst. So a
stringent control of blood sugar is essential to reduce thirst.
11. Since hot weather increases one’s thirst, any measure taken to live
in cooler comfort is desirable and recommended.
CHP. 25. Diet in Chronic Kidney Disease 201.
How to measure and consume precisely the prescribed
amount of fluid per day?
- Fill a container with water. equal to the exact amount of fluid
prescribed by the doctor for daily intake.
- The patient must bear in mind that no more than that amount of fluid
intake is permitted for the day.
- Each time the patient consumes a certain amount, fluid should be
observed. The same amount of water should be removed from the
water container and discarded
- When the container has no more water, the patient realizes that his
limit of fluid intake for the day has been reached and no more is to
be drunk. The patient is advised to distribute total fluid intake evenly
throughout the day to avoid the need of additional fluid.
- This control method is to be repeated every day.
- By this simple but very effective method the prescribed volume of
fluid can be precisely delivered to the patient and fluid intake can be
4. Salt (Sodium) Restriction in Diet
Why are CKD patients advised low sodium diet?
Sodium in our diet is important for the body to maintain blood volume
and to control blood pressure. Kidneys play an important role in the
regulation of sodium. In patients with CKD, kidneys cannot remove
excess sodium and fluid from the body so sodium and water build up in
Increased amount of sodium in the body leads to increased thirst,
swelling, shortness of breath and increase in blood pressure. To prevent
or reduce these problems, the patients of CKD must restrict sodium
intake in diet.
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What is the difference between sodium and salt?
The words sodium and salt are routinely used as synonyms. Common
salt is sodium chloride which contains 40% sodium. Salt is the principle
source of sodium in our diet. But salt is not the only source of sodium.
There are quite a few other sodium compounds in our food, such as:
- Sodium alginate: Used in ice-cream and chocolate milk.
- Sodium bicarbonate: Used as baking powder and soda.
- Sodium benzoate: Used as a preservative in sauce.
- Sodium citrate: Used to enhance flavor of gelatin, desserts and
- Sodium nitrate: Used in preserving and coloring processed meat.
- Sodium saccharide: Used as artificial sweetener.
- Sodium sulfite: Used to prevent discoloration of dried fruits.
The above mentioned compounds contain sodium but are not salty in
taste. Sodium is “hidden” in these compounds.
How much salt should one take?
Average intake of salt in Indian population is about 6 to 8 grams per
day. Patients with CKD should take salt according to the
recommendation of the doctor. CKD patients with swelling and high
blood pressure are usually advised to take about three grams of salt
Which foods contains high amount of sodium?
Foods high in sodium are:
1. Table salt (common salt), baking powder.
2. Papad, salted pickles, salted chutney, sauce, chat masala and
3. Baked food items like biscuits, cakes, pizza and breads.
4. Foods containing cooking soda or baking powder e.g., Indian foods
CHP. 25. Diet in Chronic Kidney Disease 203.
such as ganthiyas, pakodas, dhoklas, handwa, samosa, ragda
patties, dahi vadas etc.
5. Wafers, chips, popcorn, salted groundnuts, salted dry fruits like
cashew nuts, pistachios, canned foods etc. and also avoid
Readymade salted Indian snacks like sev, chivada, chakri, mathri,
6. Commercial salted butter and cheese.
7. Instant foods like noodles, spaghetti, macaroni, cornflakes etc.
8. Vegetables like cabbage, cauliflower, spinach, fenugreek leaves,
radish, beetroot, coriander leaves etc.
9. Salted lassi, masala soda, fresh lime and coconut water.
10. Drugs like sodium bicarbonate tablet, antacid, laxatives etc.
11. Non-vegetarian foods like meat, chicken and animal body organs
like kidney, liver and brain.
12. Sea food like crab, lobster, oyster and shrimp and oily fish like
columbi, kurang, kekda, bangada etc and dried fishe.
Practical Tips to Reduce Sodium in Food
1. Restrict salt intake and avoid extra salt and baking soda in diet.
Cook food without salt and add permitted amount salt separately.
This is the best option to reduce salt intake and ensure consumption
of prescribed amount of salt in everyday diet.
2. Avoid food with high sodium content (as listed above).
3. Do not serve salt and salty seasonings at the table or altogether
remove the salt shaker from the dining table. Do not add salt in
food like salad, buttermilk, rice, chapatti, bhakhary, parathas etc.
4. Carefully read labels of commercially available packaged and
processed foods. Look not only for salt but also for other sodium
containing compounds. Carefully check the labels and choose
“sodium-free” or “low-sodium” food products.
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5. Check sodium content of medicine.
6. Boil vegetables with high sodium content. Throw away the water.
This can reduce sodium content in vegetables.
7. To make low salt diet tasty, one can add garlic, onion, lemon juice,
amchur, bay leaf, tamarind pulp, vinegar, cinnamon, cardamom,
cloves, saffron, green chilies, nutmeg, black pepper, cumin, fennel,
poppy seeds etc.
8. Caution! Avoid the use of salt substitutes as they contain high amount
of potassium. High potassium content of salt substitute can raise
the potassium levels in blood to dangerous levels in CKD patients.
9. Do not drink softened water. In the process of water softening,
calcium is replaced by sodium. Water purified by reverse osmosis
process is low in all minerals including sodium.
10. While eating at restaurants select food that contains less sodium.
5. Potassium Restriction in Diet
Why are CKD patients advised to restrict potassium in diet?
Potassium is an important mineral in the body. Potassium is needed in
the body for the proper functioning of muscles and nerves and to keep
Normally, the level of potassium in body is balanced by eating potassium
containing foods and removal of excess potassium in the urine. Removal
of excess potassium in the urine may be inadequate in a patient with
chronic kidney disease which can lead to high level of potassium in the
blood (a condition known as hyperkalemia). Between the two kinds of
dialysis patients, the risk of hyperkalemia is lesser in peritoneal dialysis
compared to that in hemodialysis. The risk differs in both groups because
the process of dialysis is continuous in peritoneal dialysis while it is
intermittent in hemodialysis.
High potassium levels can cause severe muscle weakness or an irregular
heart rhythm which can be dangerous. When potassium is very high,
CHP. 25. Diet in Chronic Kidney Disease 205.
the heart can stop beating unexpectedly and cause sudden death. High
potassium level can be life threatening without noticeable manifestations
or symptoms (and therefore it is known as a silent killer).
To avoid serious consequences of high potassium, CKD patients are
advised to restrict potassium in diet.
What is normal potassium level in blood? When is it
- Normal level of potassium in blood is 3.5 mEq/l to 5.0 mEq/l.
- When the level of potassium reaches 5.0 to 6.0 mEq/l, it needs
modification in diet.
- When the level of potassium is greater than 6.0 mEq/l, it is dangerous
and needs active intervention to reduce it.
- When the level of potassium is greater than 7.0 mEq/l, it can be life
threatening and needs urgent treatment.
Classification of eatables according to potassium levels
To maintain proper control of potassium in blood, food intake must be
modified as per the doctor’s advice. On the basis of potassium contents,
foods are classified in three different groups (high, medium, and low
potassium containing foods).
High potassium = More than 200 mg/ 100 gms of food
Medium potassium = 100 to 200 mg/ 100 gms of food
Low potassium = Less than 100 mg/ 100 gms of food
Foods - High in Potassium
- Fruits: Amla, fresh apricot, ripe banana ripe, cherries, chikoo, fresh
coconut, custard apple, grapes, gooseberry, kiwi fruit, lemon, ripe
mango, musk melon, mosambi, peach, plum and sapota.
- Vegetables: Amaranth, brinjal, broccoli, cluster beans, colocasia,
coriander, drumstick, mushroom, raw papaya, potato, spinach, sweet
potato and yam (suran).
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- Dry fruits:
Almond, cashew nut, dates, dry figs, raisins and walnut.
Bajra, ragi and wheat flour.
Black gram dal, bengal gram dal, bengal gram (whole),
chana, chana dal, green gram dal, lentil dal, masoor dal, mung, red
gram, red split lentils and tur dal.
Cumin seeds, coriander seeds, dried red chili and
- Non-vegetarian food:
Fish like anchovy, mackerel, rohu, white
pomfret; shell fish like prawns, lobster and crabs and beef.
Bournvita, coconut water, coffee, condensed milk, drinking
chocolate, fresh fruit juices, rasam (dal), soup, beer, wine and many
Chocolate, cadbury, chocolate cake, chocolate
ice cream, Lona salt (salt substitute), potato chips and tomato sauce.
Foods - Medium in Potassium
Lichee, sweet lime, pomegranate and water melon.
Beet root, raw banana, bitter gourd, cabbage, carrot,
celery, cauliflower, french beans, okra (ladies finger), onion, pumpkin,
radish, sweet corn, safflower leaves and tomatoes.
Barley, general purpose flour (maida), jowar, noodles made
from wheat flour, rice flakes (pressed rice, poha) and wheat
- Non-vegetarian food:
Cital, hilsa, katla, magur, liver.
Cow milk and curd.
Black pepper, cloves, cardamom, garam masala
(mixture of Indian spices).
CHP. 25. Diet in Chronic Kidney Disease 207.
Foods - Low in Potassium
- Fruits: Apple, blackberries, cherries, guava, oranges, ripe papaya,
pear, pineapple, rose apple (jambu fruit) and strawberries.
- Vegetables: Bottle gourd(dudhi), broad beans (papdi), capsicum,
ridged gourd (turiya), cucumber, fenugreek leaves (methi), garlic,
lettuce, green peas, raw mango and pointed gourd (parvar), tinda
- Cereals: Rice, rava and wheat semolina.
- Pulses: Green.peas
- Non-vegetarian food: Beef, lamb, pork, chicken and egg.
- Drinks: Buffalo milk, coca-cola, fanta, lemonade, lime juice in water,
limca, rimzim and soda.
- Miscellaneous: Dried ginger, honey, mint leaves, mustard, nutmeg
Practical Tips to Reduce Potassium in Food
1. Take one fruit per day, preferably with low potassium.
2. Take one cup of tea or coffee per day.
3. Vegetables with potassium should be taken after reducing the amount
of potassium (as mentioned below).
4. Avoid coconut water, fruit juices and foods with high potassium
contents (as listed above).
5. Almost all food contains some potassium, so the key is to choose
food with a low potassium level, when possible.
6. Restriction of potassium is necessary not only for predialysis CKD
patients, but is also necessary even after initiating dialysis.
How to reduce potassium content in vegetables?
Peel, and cut vegetables in to small pieces.
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- Wash them with lukewarm water and put them in a large pot.
- Fill the pot with hot water (the quantity of water must be four to five
times the volume of vegetables) and soak them for at least one hour.
- After soaking the vegetables for 2 - 3 hours, rinse them three times
with warm water.
- Subsequently boil the vegetables with extra water. discard the water.
- cook the boiled vegetables as desired.
- In this way you can reduce the amount of potassium in vegetables,
but not completely. So it is preferable to avoid high potassium
containing vegetables or take them in small quantity.
- As vitamins are lost in cooked vegetables, vitamin supplements should
be taken as per the doctor’s advice.
Special tips for leaching potassium from potatoes
- Dicing, slicing or grating potatoes into smaller pieces is important.
Maximize surface of the potatoes exposed to water by this method.
- The temperature of the water used to either soak or boil the potatoes
makes the difference.
- Using large amount of water to soak or boil potatoes is helpful.
6. Phosphorus Restriction in Diet
Why must CKD patient take low phosphorus diet?
- Phosphorus is a mineral essential to keep bones strong and healthy.
Usually extra phosphorus present in food is removed in urine and
thereby the blood phosphorus levels are maintained.
- Normal value of phosphorus in blood is 4.0 to 5.5 mg/dl.
- In CKD patients the extra phosphorus taken in food is not excreted
in urine and so the blood level rises. This increased phosphorus
drains out calcium from the bones making them weak.
CHP. 25. Diet in Chronic Kidney Disease 209.
Increase in phosphorus level can lead to many problems like itching,
weakness of muscles and bones, bone pains, bone stiffness and
joint pain. The stiffness of bone results in increased susceptibility to
consumption of which food with high phosphorus content
should be reduced or avoided?
Food containing high phosphorous are:
- Milk and dairy products: butter, cheese, chocolate, condensed milk,
icecream, milk shake, paneer.
- Dry fruits: cashew nuts, almonds, pistachios, dry coconut, walnut.
- Cold drinks: dark colas, Fanta, Mazza, Frooti, beer.
- Carrot, colacasia leaves, corn, groundnut, fresh peas, sweet potato.
- Animal protein: meat, chicken, fish and egg.
7. High Vitamin and Fibers Intake
CKD patients suffer from inadequate supply of vitamins during
predialysis period due to reduction of food intake, special method of
cooking to remove excess potassium and poor appetite. Certain vitamins
– especially water soluble vitamins B and C, folic acid etc – are lost
To compensate for inadequate intake or loss of these vitamins CKD
patients usually need supplementation of water-soluble vitamins and
trace elements. High fiber intake is beneficial in CKD. So patients are
advised to take more fresh vegetables and fruits rich in vitamin and
Designing the Daily Food
For CKD patients daily food intake and water intake is planned and
charted out by the dietitian in accordance with the advice of the
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Common principles for the diet plan are:
1. Water and liquid food intake:
Fluid intake restriction must be as
per the doctor’s advice. Daily weight chart must be maintained.
Any improper gain in weight indicates increased fluid intake.
To ensure that the body gets adequate calories
along with cereals and pulses, the patient can take sugar or glucose
containing food, provided he/she is not diabetic.
Milk, cereals, pulses, eggs, chicken are the main source
of protein. Those patients of CKD who are yet not on dialysis are
advised to curtail protein in diet. They are advised to take 0.8
grams per kilogram of body weight per day. Once dialysis is started,
patient needs high-protein diet (especially the patients on peritoneal
Avoid eating animal proteins such as meat, chicken and fish which
contain high protein, potassium and phosphorous. All animal protein
can be harmful to CKD patients.
The amount of fat in food must be reduced but total curtailing
of butter; ghee etc from food can be dangerous. Generally soyabean
oil, groundnut oil is useful for the body but it is desirable to take
these oils in limited quantity.
Most patients are advised to take low salt diet. Do not add
salt at the table. Do not take food cooked with baking powder;
and if you take it see that it is taken in restricted amount. Avoid use
of salt substitutes as they contain high amount of potassium.
Rice or rice products like flattened rice (poha), kurmura
(puffed rice) can be taken. To avoid monotony of taste one can
take various cereals like wheat, rice, poha, sago, semolina, all
purpose flour, cornflakes in rotation. Barley, bajra, and corn can
be taken but in a small quantity.
CHP. 25. Diet in Chronic Kidney Disease 211.
7. Pulses: Various dals should be taken in right quantities in rotation
so that the change in taste can make food palatable. As dal is liquid,
the amount of fluid consumed with it must be taken into account. If
possible it is preferable to make dal thicker in consistency rather
than with more water. The amount of dal must be taken as per the
8. To reduce potassium from dals it is essential that after washing,
they must be soaked in hot water and the water discarded.
Subsequently boil them with water and discard extra water after
boiling. The dal, can now be cooked as per your taste. As an alter-
native to dal and rice, one can take khichadi or dosa.
9. Vegetable: Vegetables with low potassium can be liberally taken.
But vegetables with high potassium must be processed to remove
potassium before consumption. To improve taste lemon juice can
10. Fruits: Fruits with low potassium content like apple, papaya, berry
can be taken but only once a day. On the day of dialysis patient
can take any one fruit. Fruit juice and coconut water must be
11. Milk and milk products: 300 to 350 ml of either milk or milk
products like kheer, ice cream, curd, maththa can be taken. Again,
to avoid the extra liquid, limit the volume of these products.
12. Cold drinks: Pepsi, Fanta, Frooti must be avoided. Do not take
fruit juice or coconut water.
13. Dry fruits: Dry fruits, groundnut, sesame seeds, fresh or dry
coconut must be avoided.