The document provides information on dietary modifications for renal disorders. It discusses the functions of the kidneys and defines acute and chronic renal diseases. For acute renal diseases, it outlines symptoms, risk factors, causes, diagnosis, treatment including diet modifications and dialysis. For chronic renal disease, it again discusses symptoms, causes and complications. It provides dietary guidelines for renal disease not requiring dialysis, including the DASH diet. Diet recommendations are tailored based on kidney disease stage and include limiting protein, sodium and phosphorus.
2. KIDNEYS
Introduction to Kidneys
Human kidneys are bean-shaped organs located near the middle of the back on both sides where
they are protected by lower ribs and cushioned by the surrounding muscles and fat. Each kidney
is about the size of a clenched fist and weighs about 150 grams. Each kidney has about one
million nephrons, which are tiny, filtering units. In the nephrons, capillaries or tiny blood vessels
intertwine with tubules, which are urine-carrying tubes. The nephrons make it possible for the
kidneys to filter the body’s entire blood supply.
Function of Kidneys
Kidneys mainly process the waste products and excess fluid in your blood. The waste products
result from our body’s metabolic processes. In addition, waste is also a by-product of the food
we eat. Our body uses food for energy and self-repairs. After it has absorbed what it needs from
the food, the remaining waste products are sent to the blood.
A complicated chemical exchange takes place as the blood is filtered by the nephrons. The
filtering process removes the waste, toxins and excess water from the blood to form urine. Urine
flows from the kidneys to the ureters and then stored in the bladder until we urinate. In addition,
the kidneys regulate the chemical balance in our body.
They release three important hormones:
Erythropoietin aids in red blood cell formation
Renin, maintains a normal blood pressure
The active form of Vitamin D, which helps keep our bones strong
3. ACUTE RENAL DISEASES
Definition
“Acute renal disease also called acute renal failure happens when your kidneys suddenly the
ability to eliminate excess salts, fluids, and waste materials from the blood”
This elimination is the core of your kidneys’ main function. Body fluids can rise to dangerous
levels when kidneys lose their filtering ability. The condition will also cause electrolytes and
waste material to accumulate in your body, which can also be life-threatening. Acute renal
failure can be life-threatening and requires intensive treatment. However, it may be reversible. If
you’re in good health otherwise, recovery is possible.
Symptoms
The symptoms of acute renal failure include:
Bloody stools
Breath odor
Generalized swelling or fluid retention
Fatigue
Pain between ribs and hips
Hand tremor
Bruising easily
Changes in mental status or mood, especially in older adults
Decreased appetite
Decreased sensation, especially in your hands or feet
Prolonged bleeding
4. Seizures
Nausea
vomiting
Slow sluggish movements
High blood pressure
A metallic taste in your mouth
Risk factors
The chances of acquiring acute kidney failure are greater if you’re an older person or if you have
any of the following long-term health problems:
Kidney disease
Diabetes, especially if it’s not well controlled
High blood pressure
Heart failure
Morbid obesity
Liver disease
Causes
Acute renal diseases can occur for many reasons. Among the most common reasons are:
Acute tubular necrosis (ATN)
Severe or sudden dehydration
Toxic kidney injury from poisons or certain medications
Autoimmune kidney diseases, such as acute nephritic syndrome and interstitial nephritis
Urinary tract obstruction
Reduced blood flow can damage your kidneys. The following conditions can lead to decreased
blood flow to your kidneys:
Low blood pressure
Burns
Dehydration
Hemorrhage
Injury
Septic shock
Serious illness
Surgery
5. Certain disorders can cause clotting within your kidney’s blood vessels, and this can lead to
acute renal failure. These conditions include:
Hemolytic uremic syndrome
Idiopathic thrombocytopenic thrombotic purpura (ITTP)
Malignant hypertension
Transfusion reaction
Scleroderma
Some infections, such as septicemia and acute pyelonephritis, can directly injure your
kidneys.
Pregnancy can also cause complications that harm the kidneys, including placenta
previa and placenta abruption.
Prevention
Preventing and treating illnesses that can lead to acute renal diseases having a healthy
lifestyle that includes regular physical activity and a sensible diet can help to prevent kidney
failure. Work with your doctor to manage existing medical conditions that could lead to acute
renal diseases.
Diagnosis
If you have acute kidney failure, you may have generalized swelling. The swelling is due to fluid
retention.
Using a stethoscope, your doctor may hear crackling in the lungs. These sounds can signal fluid
retention.
Results of laboratory tests may also show abnormal values, which are new and different from
baseline levels. Some of these tests include:
Blood urea nitrogen (BUN)
Serum potassium
Serum sodium
Estimated glomerular filtration rate (EGFR)
Urinalysis
Creatinine clearance
Serum creatinine
An ultrasound is the preferred method for diagnosing acute kidney failure. However,
abdominal X-ray, abdominal CT scan, and abdominal MRI can help your doctor determine if
there’s a blockage in your urinary tract. Certain blood tests may also reveal underlying causes of
acute kidney failure.
6. Treatment
Your treatment will depend on the cause of your acute renal disease. The goal is to restore
normal kidney function. Preventing fluids and wastes from building up in your body while your
kidneys recover is important. In the majority of cases, a kidney specialist called a nephrologist
makes an evaluation.
Diet
Your doctor will restrict your diet and the amount of liquids you eat and drink. This will reduce
the buildup of toxins that the kidneys would normally eliminate. A diet high in carbohydrates
and low in protein, salt, and potassium is usually recommended.
Medications
Your doctor may prescribe antibiotics to treat or prevent any infections that occur at the same
time. Diuretics may help your kidneys eliminate fluid. Calcium and insulin can help you avoid
dangerous increases in your blood potassium levels.
Dialysis
You may need dialysis but it’s not always necessary and it will likely only be temporary.
Dialysis involves diverting blood out of your body into a machine that filters out waste. The
clean blood then returns to your body. If your potassium levels are dangerously high, dialysis can
save your life.
Dialysis is necessary if there are changes in your mental status or if you stop urinating. You may
also need dialysis if you develop pericarditis or inflammation of the heart. Dialysis can help
eliminate nitrogen waste products from your body.
CHRONIC RENAL DISEASE
Definition
Chronic kidney disease, also called chronic kidney failure, describes the gradual loss of kidney
function. Your kidneys filter wastes and excess fluids from your blood, which are then excreted
in your urine. When chronic kidney disease reaches an advanced stage, dangerous levels of fluid,
electrolytes and wastes can build up in your body.
Symptoms
7. Signs and symptoms of chronic kidney disease develop over time if kidney damage progresses
slowly. Signs and symptoms of kidney disease may include:
Nausea
Vomiting
Loss of appetite
Fatigue and weakness
Sleep problems
Changes in how much you urinate
Decreased mental sharpness
Muscle twitches and cramps
Swelling of feet and ankles
Persistent itching
Chest pain, if fluid builds up around the lining of the heart
Shortness of breath, if fluid builds up in the lungs
High blood pressure (hypertension) that's difficult to control
Causes
Chronic kidney disease occurs when a disease or condition impairs kidney function, causing
kidney damage to worsen over several months or years. Diseases and conditions that cause
chronic kidney disease include:
Type 1 or type 2 diabetes
High blood pressure
Glomerulonephritis , an inflammation of the kidney's filtering units (glomeruli)
Interstitial nephritis , an inflammation of the kidney's tubules and surrounding structures
Polycystic kidney disease
Prolonged obstruction of the urinary tract, from conditions such as enlarged prostate,
kidney stones and some cancers
Vesicoureteral reflux, a condition that causes urine to back up into your kidneys
Recurrent kidney infection, also called pyelonephritis
Kidney cancer:
It is also called renal cancer is a disease in which kidney cells become malignant (cancerous) and
grow out of control, forming a tumor. Almost all kidney cancers first appear in the lining of tiny
tubes (tubules) in the kidney. This type of kidney cancer is called renal cell carcinoma.
Kidney failure:
8. Kidney failure occurs when your kidneys lose the ability to filter waste from your blood
sufficiently. Body becomes overloaded with toxins if your kidneys can’t do their regular job.
This can lead to kidney failure and even be life-threatening if it’s left untreated.
PhosphateandCalciumimbalance:
Phosphorus imbalance refers to conditions in which the element phosphorus is present in the
body at too high a level (hyperphosphatemia) or too low a level (hypophosphatemia).
Hyper phosphotemia:
Having a high level of phosphate or phosphorous in your blood is known as hyperphosphatemia.
Phosphate is an electrolyte, which is an electrically charged substance that contains the mineral
phosphorous.
Hypocalcemia:
It is a condition in which the calcium level in your blood is above normal. Too much calcium in
your blood can weaken your bones, create kidney stones, and interfere with how your heart and
brain work.
RenalDiseasedue to other diseases:
Diabetic nephropathy
Nephropathy is a general term for the deterioration of proper functioning in the kidneys. At an
advanced level, this is called end-stage renal disease or ESRD. ESRD often stems from diabetes,
with diabetes causing just under half of all cases. Diabetic nephropathy can affect people with
both type 1 and type 2 diabetes.
Renal osteodystrophy:
It is a bone disease that occurs when your kidneys fail to maintain proper levels of calcium and
phosphorus in the blood. It's common in people with kidney disease and affects most dialysis
patients.
Hypertensive Nephropathy:
It is a disease of the kidneys. The vasculature of the kidneys is damaged with an increase in
blood pressure.
DIALYSIS
The word ‘dialysis’ means filtering, or the selective removal of certain substances from the
blood. If by artificial means, we can remove enough of the poisonous wastes, water and salts that
have built up due to kidney failure, then a reasonable level of health can be restored.
9. There are two forms of dialysis,
Peritoneal Dialysis, in which the body’s abdominal lining is used as a filter.
Haemodialysis, in which a special machine acts as a substitute for the kidneys
DIETARY GUIDELINES FOR RENAL DISEASE NOT REQUIRING
DIALYSIS
DASH Diet:
The DASH (Dietary Approaches to Stop Hypertension) Diet has been recommended by the
National Kidney Foundation and approved by The National Heart, Lung and Blood Institute, The
American Heart Association, the Dietary Guidelines for Americans, and also forms the basis for
the USDA MyPyramid.
Although it was first intended only to decrease 1) blood pressure and 2) reduce risk of
cardiovascular diseases and stroke, studies on the DASH have demonstrated that the DASH diet
also helps in 3) reducing risk of many cancers, 4) prevents kidney stone formation, and 5) helps
to manage acute and chronic renal disease. The DASH diet should not be used by people on
dialysis. Individuals on dialysis have a special dietary need that requires different diets.
Here is the modified DASH diet for a 2,200 caloriediet of a renal disease
patient:
Food Group Daily Servings Calories/ Nutrients Serving Size
Grains 6–8
80 calories
2 g of protein
150 mg of sodium,
30 mg of phosphorus
50 mg of potassium
-1 Slice bread
-½ hamburger bun or bagel
-1 cup unsweetened cereal or
-½ cup cooked cereal
-½ cup cooked rice, pasta, or
cereal
-4 (2 inch) unsalted crackers
Vegetables
4–5 (if only low
potassium)
30 calories
2 g of protein
50 mg of sodium
50 mg of phosphorus.
-½ cup cooked green beans,
cabbage, cauliflower, beets or
corn
-1 cup cooked eggplant
-1 cup raw cucumber, alfalfa
10. Low potassium (less than
150 mg)
sprouts, cabbage, cauliflower
-1 cup raw leafy vegetable
such as lettuce
-¼ cup cooked or ½ cup raw
mushrooms or onions
Vegetables
1–2 (if only
medium
potassium)
30 calories, 2 g of protein, 50
mg of sodium, and 50 mg of
phosphorus.
Medium potassium (150 to
250 mg)
-½ cup cooked broccoli,
celery, green peas, summer
squash, zucchini
- 1 cup cooked turnips
-1 cup raw broccoli, celery or
zucchini
Fruits
4–5 (if only low
potassium)
60 calories
0 g protein
0 mg sodium
150 mg of phosphorus.
Low potassium (less than
150 mg)
Each serving is ½ cup unless
mentioned
-1 small apple, apple juice, or
applesauce
-Cranberries or cranberry
juice
-Fresh or light syrup canned
pears
-Fresh or Light syrup canned
peaches
-Grapes or grape juice
-Pineapple
-Strawberries
-1 tangerine
-Watermelon
Fruits
1-2 (if only
medium
potassium)
60 calories, 0 g protein, 0 mg
sodium, and 150 mg of
phosphorus.
Medium potassium (150 to
250 mg)
-Berries
-Cherries
-Cantaloupe
-Mango
11. Each serving is ½ cup unless
mentioned
-Papaya
-Grapefruit or grapefruit juice
Lean meats,
poultry, and fish
4 or less
75 calories
7 g of protein
average of 65 mg of sodium
115 mg of potassium
70 mg of phosphorus
-1 oz cooked beef, mutton or
poultry
-1 oz fresh or frozen fish,
shrimp, lobster, crab, clam,
tuna, unsalted salmon
Other Protein
Foods
2 or less
90 calories
7 g of protein
average of 100 mg of sodium
100 mg of potassium
120 mg of phosphorus
-1 large whole egg
-¼ cup low-cholesterol egg
substitute
-1 ounce milk or yogurt
-11/2 ounce cheese
-¼ cup cottage cheese or tofu
-1/3 cup or 1 ½ ounce
unsalted nuts
-2 tablespoons peanut butter
Fats and oils 2–3
About 45 calories
Very little protein
55 milligrams of sodium
10 milligrams of potassium
5 milligrams of phosphorus.
-1 teaspoon soft margarine
-1 teaspoon vegetable oil
-1 tablespoon mayonnaise
-1 tablespoon oil based salad
dressing
-2 tablespoon mayonnaise
based salad dressing.
Sweets and added
sugars
5 or less per
week
These contain mostly
carbohydrates and empty
calories (calories that do not
-1 tablespoon sugar
-1 tablespoon jelly or jam
-½ cup sorbet, gelatin
12. There is no one diet that is good for everyone with kidney disease. Kidney disease is complicated
and requires close monitoring by a dietitian and your doctor. Laboratory tests and follow-up
evaluations are the only way to ensure your disease is being managed appropriately.
Diet Basedon StagesofKidney Disease
There are 5 stages of chronic kidney disease. The diet changes you need to make are based on
your stage of kidney disease.
Limit protein in all stages of kidney disease. This limits the amount of work your kidneys have
to do. Foods that are high in protein are meat, poultry (chicken and turkey), fish, eggs, and dairy
(milk, cheese, yogurt). Your healthcare provider will tell you how much protein to eat each day.
Limit sodium intake to less than 2,300 milligrams (mg) each day. Ask your dietitian or
healthcare provider how much sodium you can have each day. The amount of sodium you should
have depends on your stage of kidney disease and whether you have hypertension. Table salt,
canned foods, soups, salted snacks, and processed meats, like deli meats and sausage, are high in
sodium.
Limit the amount of phosphorus you eat. Your kidneys cannot get rid of extra phosphorus that
builds up in your blood. This may cause your bones to lose calcium and weaken. Foods that are
high in phosphorus are dairy products, beans, peas, nuts, and whole grains. Phosphorus is also
found in cocoa, beer, and cola drinks. Your healthcare provider will tell you how much
phosphorus you can have each day.
Limit potassium if your potassium blood levels are too high. Your dietitian or healthcare
provider will tell you if you need to limit potassium.
Limit liquids as directed. Your healthcare provider may recommend that you limit liquids in
stages 4 and 5 of kidney disease. If your body retains fluids, you will have swelling and fluid
may build up in your lungs. This can cause other health problems, such as shortness of breath.
DIETARY GUIDELINES FOR RENAL DISEASE NOT REQUIRING
DIALYSIS
As, kidneys are not able to get rid of enough waste products and fluids from your body. It is
important that you have the right amounts of protein, calories, vitamins and minerals in your diet.
Here are some general guidelines:
provide good nutrition) -1 cup lemonade
13. Protein
Body needs protein for growth, building muscles and repairing tissue.
After our body uses the protein in the foods we eat, a waste product called urea is left. Since our
kidneys are not able to get rid of this urea, we may have too much in our blood. Dialysis and our
diet are important to keep the urea level down.
Along with the clearing of urea, our body loses proteins that are normally retained in your blood.
We will need to eat more protein to replace what is lost. The type of protein we eat is also very
important. High quality protein should be eaten at each meal. It comes from animal sources such
as eggs, fish, chicken and meat. Low quality protein needs to be limited in our diet. It comes
from plant sources such as vegetables and grains.
Calories
Calories give energy to our body. One source of calories is the food we eat. Another source is the
sugar in dialysate solution that can affect our body because:
It takes extra fluid out of the body.
It is taken in by our body.
It can cause unwanted weight gain.
Potassium
Potassium is a mineral found naturally in foods that is dangerous when we have too much or too
little. It is plentiful in dried fruits, dried beans and peas, nuts, meat, milk, fruits and vegetables
and also in salt substitutes. Both high and low levels of potassium in our body are dangerous to
our heart.
Fluid and Sodium
Sodium is a mineral that is found naturally in foods and can affect our blood pressure. It is found
in large amounts in table salt and in canned foods and processed meats (cold cuts).
Watching sodium content can help to control thirst and weight gain. It may also lower use of
high-sugar solutions.
Phosphorus
Phosphorus is a mineral present in all foods. It is found in large amounts in milk, cheese, nuts,
dried beans and peas.
Eating foods high in phosphorus will raise the phosphorus in blood and this can cause calcium to
be pulled from the bones. This will make bones weak and cause them to break easily. To help
14. control the phosphorus in our blood, we may need to take medicine called a phosphate binder. It
should be taken with meals and snacks as ordered by your doctor. A renal dietitian can also tell
about protein foods that are lower in phosphorus.
Vitamins and Minerals
The dialysis treatment washes some water-soluble vitamins out of the body. If we are not getting
all the vitamins and minerals we need from the foods we eat, vitamin and mineral supplements
may be recommended. It is important to take only what is ordered and suitable for us. Certain
vitamins and minerals can be harmful to persons on dialysis.
Servings and foods recommended to dialysis patients according to food groups
Meat products
People on dialysis need to eat more protein. Protein can help maintain blood protein levels and
improve health. Eat a high protein food (meat, fish, poultry, fresh pork, or eggs) at every meal, or
about 8-10 ounces of high protein foods every day.
Even though peanut butter, nuts, seeds, dried beans, peas, and lentils have protein, these foods
are generally not recommended because they are high in both potassium and phosphorus.
Grains and Cereals
Unless we need to limit our calorie intake for weight loss or manage carbohydrate intake for
blood sugar control, we may eat, from this food group. Grains, cereals, and breads are a good
source of calories. Most people need 6 -11 servings from this group each day.
Avoid “whole grain” and “high fiber” foods (like whole wheat bread, bran cereal and brown rice)
to help you limit your intake of phosphorus.
Dairy products
Limit the intake of milk, yogurt, and cheese to ½-cup milk or ½-cup yogurt or 1-ounce
cheese per day. Most dairy foods are very high in phosphorus.
The phosphorus content is the same for all types of milk – skim, low fat, and whole. If we do eat
any high-phosphorus foods, take a phosphate binder with that meal.
Dairy foods “low” in phosphorus:
Butter and tub margarine
Cream cheese
Heavy cream
15. Ricotta cheese
Brie cheese
Non-dairy whipped topping
Some of the high fat foods listed above may not be good choices for cardiovascular diseases,
cholesterol and obesity.
Fruits
All fruits have some potassium, but certain fruits have more than others and should be limited or
totally avoided. Limiting potassium protects your heart. Eat 2-3 servings of low potassium fruits
each day. One serving = ½-cup or 1 small fruit or 4 ounces of juice.
Choose low potassium fruits:
Apple (1)
Berries (½ cup)
Cherries (10)
Fruit cocktail, drained (½ cup)
Grapes (15)
Peach (1 small fresh or canned, drained)
Pear, fresh or canned, drained (1 halve)
Pineapple (½ cup canned, drained)
Plums (1-2)
Tangerine (1)
Watermelon (1 small wedge)
Limit or avoid high potassium fruits:
Oranges and orange juice
Kiwis
Nectarines
Raisins and dried fruit
Bananas
Melons (cantaloupe and honeydew)
Fruit juices:
Apple cider
Cranberry juice cocktail
Grape juice
Lemonade
16. Vegetables
All vegetables have some potassium, but certain vegetables have more than others and should be
limited or totally avoided. Limiting potassium intake protects your heart. Eat 2-3 servings of
low-potassium vegetables each day. One serving = ½-cup.
Choose low potassium vegetables:
Broccoli (raw or cooked from frozen)
Cabbage
Carrots
Cauliflower
Celery
Cucumber
Eggplant
Garlic
Green and Wax beans (“string beans”)
Lettuce-all types (1 cup)
Onion
Peppers-all types and colors
Radishes
Zucchini and Yellow squash
Limit or avoid high potassium vegetables:
Potatoes (including French Fries, potato chips and sweet potatoes)
Tomatoes and tomato sauce
Winter squash
Pumpkin
Asparagus (cooked)
Avocado
Beets
Cooked spinach
Sample menu plan for dialysis patients:
Breakfast:
1/4 cup evaporated milk with 1/4 cup distilled water
1 box of cereal
1/2 cup of peaches
17. Mid day snack:
5 vanilla wafers or
Graham cracker (1 ½ squares)
Lunch:
Peanut butter sandwich (2 slices of bran bread and 2 tablespoon of peanut butter)
1/2 cup pears
1/2 cup fruit juice
Evening snack:
1/2 cup apples or
1/2 cup canned applesauce
Dinner:
Chicken sandwiches (2 slices of bran bread, 1/2 cup low sodium chicken and 2
tablespoons of mayonnaise)
1/2 cup carrots
1/2 cup cranberry juice
Bed time snack:
5 vanilla wafers or
Graham cracker (1 ½ squares)
