Paying attention to carbohydrates is essential when you are on a kidney diet. Carbohydrate foods can give you the energy you need to go about your daily activities. Whether you have early-stage kidney disease, are on a particular type of dialysis treatment, or have diabetes will determine how many carbohydrates you should have per day. 

Carbohydrates, fiber, and dialysis

Some carbohydrate foods contain fiber, which plays a vital role in protecting your heart, blood vessels, and colon. 
If you have been diagnosed with chronic kidney disease (CKD), you are more susceptible to heart disease.
High-fiber diets help lower cholesterol levels, reducing your risk for heart attack or other cardiovascular conditions. Lowering your cholesterol may even help you stay off certain medications. Some studies show that increased fiber in the diet can reduce blood pressure and inflammation. 
Many people on dialysis complain of gastrointestinal (GI) symptoms, such as constipation or diarrhea. Fiber can help reduce these symptoms, as well as help control weight and blood-sugar levels. Ask your nephrologist and renal dietitian which high-fiber foods may work in your kidney diet.

What is a carbohydrate?

A carbohydrate is a nutrient found in many foods and drinks turned into sugar (glucose) when you digest it. Any food or drink that has carbohydrates can raise your blood sugar. However, some foods and drinks will raise your blood sugar faster than others, depending on the type of carbohydrates they contain. 

There are two types of carbohydrates:
complex carbohydrates or starches, which usually raise blood sugar more slowly (it takes your body longer to digest and absorb these)
simple carbohydrates or sugars, which typically raise your blood sugar more quickly than complex carbohydrates

Diabetes and carbohydrates

Serving sizes on the kidney diet is vital for overall weight control and glucose control if you have diabetes. One serving of a carbohydrate food provides 60-100 calories and 15 grams of carbohydrate. If you are overweight, you may want to decrease the number of servings you consume. If you are underweight, consider increasing the number of carbohydrate servings. If you have diabetes, you may follow a plan called carbohydrate counting to help regulate your blood sugar. 
Consult your dietitian for individual weight or diabetes management plans. 

When you have diabetes, and kidney disease, understanding which foods contain carbohydrates and how much you can eat is essential for blood sugar control. Blood sugar levels should run between 80-120 mg/dL before eating and below 180 mg/dL two hours after eating. Taking diabetes medication prescribed by your doctor is not enough to manage blood sugar levels. Controlling diabetes includes:

  • Following a healthy diet (as instructed by your dietitian)
  • Eating at consistent meal and snack times and not skipping meals
  • Following recommended serving sizes and reading food labels
  • Balancing carbohydrate intake throughout the day
  • Checking blood sugar levels often

Carbohydrates and hemodialysis

If you do in-center hemodialysis or home hemodialysis (HHD), you may have different carbohydrate needs for your dialysis diet. Your individual need for foods containing carbohydrates is typically half of your diet. It means 40-60% of your total daily calorie intake should come from carbohydrate foods. For example, if you need 2,000 calories to meet your everyday needs, then 800-1,200 calories should come from carbohydrate foods. That equals 200-275 grams of carbohydrate a day.

Carbohydrates and peritoneal dialysis

For people on peritoneal dialysis (PD), the need for carbohydrates is less than for people on hemodialysis. In PD, a dialysate containing dextrose — a form of sugar — is used to pull waste and fluid out of the blood. Because dextrose is a carbohydrate like glucose, your body absorbs these calories, decreasing your need to consume carbohydrates in food. These excess calories can affect weight control and blood sugar management.

If you are on PD, you absorb 15% of your calorie needs from the dialysate. It means that only 35-40% of your total daily calories should come from carbohydrate foods. The remainder of your calories should come from protein foods and fat. For example, if you need 2,000 calories per day, 700-800 calories should come from carbohydrate foods. It equals 175-200 grams of carbohydrate a day. Dialysate provides approximately 300 calories throughout the day.

What is carbohydrate counting?

Carbohydrate counting is a way for you to keep track of the amount of sugar, known as carbohydrates, that you eat. If you have diabetes, it is crucial to learn about carbohydrates found in food. Keeping track of your carbohydrate intake will help you control your blood sugar levels.

Where are carbohydrates found?

You can find carbohydrates in many different foods.
Some carbohydrate foods may be used less often in your diet due to high potassium, sodium, or phosphorus content. Your nephrologist and dietitian will help you know which foods are best for you.

CARBOHYDRATES

  • WHOLE GRAIN BREAD
  • ROLLS
  • TORTILLA
  • RICE
  • PASTA
  • POTATO
  • CORN
  • DRIED BEANS
  • SODAS
  • FRUIT
  • FRUIT JUICE
  • MILK
  • YOGURT
  • CANDY
  • CAKE
  • COOKIES
  • ICE CREAM

NOT A CARBOHYDRATE

  • BEEF
  • CHICKEN
  • FISH
  • LAMB
  • BUTTER
  • MAYONNAISE
  • CARROT
  • CUCUMBER
  • LETTUCE
  • CHEESE
  • EGGS
  • PORK
  • TURKEY
  • MARGARINE
  • OIL
  • CAULIFLOWER
  • GREEN BEANS
  • ZUCCHINI

What is a serving size of carbohydrate?

A serving size of carbohydrate is the amount of food that will give you about 15 grams, or one carbohydrate serving. The serving size of carbohydrates varies depending on the type of food.

The following foods are examples of one serving of a carbohydrate food:

One slice of bread
1 cup of fresh fruit
½ cup of canned fruit
¾ cup dry cereal
½ cup hot cereal
½ cup mashed potatoes
½ cup corn

Carbohydrate Counting and Meal Planning

Important things to remember when carbohydrate counting:

-Eat at about the same time every day to keep blood sugars stable throughout the day.
-Eat the exact amounts of carbohydrates at each meal and snack.
-Eat a meal or snack every 3-4 hours to keep blood sugars even.
-Do not skip meals.

The number of carbohydrates you need will depend on your weight and activity level. In general, your renal dietitian will recommend 3 to 6 servings of carbohydrates and 1 to 3 servings at each snack. 
Your nephrologist and dietitian will help you know how many servings are best for you.

You can check food labels for the grams of carbohydrates and convert the grams into servings. For example:
15 grams = 1 serving
30 grams = 2 servings
45 grams = 3 servings

Ask your dietitian to help with your carbohydrate counting plan.

Breakfast:_______# of Carbohydrate Servings
Morning Snack:______# of Carbohydrate Servings
Lunch:_____# of Carbohydrate Servings
PM Snack:_____# of Carbohydrate Servings
Dinner:______# of Carbohydrate Servings
Bedtime Snack:_____# of Carbohydrate Servings

Blood glucose control and hypertension therapy are key factors affecting kidney function. 
Whether you count each carb gram or use one of the other meal-planning methods, you'll want to choose foods that are rich in nutrients. Opt for unprocessed whole foods, such as vegetables, fruits, whole grains, and lean proteins. Processed foods, such as packaged cookies, crackers, and other snack foods, usually contain added salt, sugar, carbohydrates, fat, or preservatives.

While this sounds like a lot, don't be overwhelmed—start by making small changes and sticking to them. Talk to your nephrologist and renal dietitian about your diet. They will help you make the best choices!

Florida Kidney Physicians offers FREE Kidney Health classes 101 to guide you through the chronic kidney disease and diet process. If you are an FKP patient, call your FKP office location and sign up today!

Sources:
*https://www.diabetes.org/healthy-living/recipes-nutrition/understanding-carbs/carb-counting-and-diabetes
*https://www.kidney.org/atoz/content/carbcount
*https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6617052/