Carbohydrates, commonly known as "Carbs," are food sources that turn into simple sugar (glucose) when digested and broken down. They are part of the three essential macronutrients that comprise our daily calorie intake. These three essential macronutrients are Carbohydrates, Protein and Fat. 

Carbohydrates provide 50-60% of the body’s energy needs for healthy individuals without any complications. Unfortunately, carbohydrate intake may be different for CKD patients who have obesity and/or diabetes. This is why carbohydrate counting is part of practicing a healthy kidney-friendly diet. Carbohydrate counting involves tracking the amount of carbohydrate intake you eat and drink in a day. 

That sounds easy to understand, right? But converting this into portion sizes for your meals may get a bit complicated.

Why manage your Carbs if you have CKD?

Carbohydrates, as mentioned earlier, are broken down into simple sugar (glucose) to provide 50-60% of the body’s daily energy needs. However, overconsumption can further complicate your condition.

Excess consumption of the required carbohydrates per day over a period of time can increase the chances of developing:

• Type II Diabetes
• Overweight
• Obesity
• CVD

There are factors that contribute to determining your carbohydrate intake, these are physical activity and health condition. 

Your health condition is very important in determining your carbohydrate intake especially for those who are diabetic or on peritoneal dialysis (PD). Diabetic CKD patients may need to closely monitor their carbohydrate intake through carbohydrate counting as this will greatly affect their blood sugar level. 

Whereas for dialysis patients, the type of dialysis will matter. Hemodialysis (HD) uses a machine to function as an artificial kidney while peritoneal dialysis (PD) uses a soft plastic tube that passes through the stomach. A fluid is used to filter the kidney, which is called a dialysate. The dialysate fluid is the reason peritoneal dialysis (PD) patients need to lessen their carbohydrate intake. The dialysate contains dextrose. Since dextrose is a form of carbohydrate, you may be advised to lessen your carbohydrate intake. 

The dialysate fluid takes up to 15% of your carbohydrate requirement; this means, if your required carbohydrate intake is at 50-60% (minus the dialysate), the remaining 35-45% would be from other carbohydrate food sources such as rice, bread, pasta etc. 

According to the American Kidney Fund,  the typical carbohydrate requirement is as follows:

• Male: 45-60 g of Carbohydrates per meal and 15-20 g of Carbohydrates for snacks
• Female: 30-45 g of Carbohydrates per meal and 15 g of carbohydrates for snacks 

Each carbohydrate-containing food item has a particular size that corresponds to the amount in grams of carbohydrates. For example, you are prescribed to eat 45 grams of carbohydrates, this does not exactly mean 45 grams of bread or rice. Later in this article, we will discuss sample portion sizes of carbohydrates and how to monitor them in your meals. 

Carbohydrate Food Sources

There are three main types of carbohydrates in food and these are:

• Starch
• Sugar 
• Fiber

Choosing the right source is important when counting carbs since not all carbs are created equal.

Let’s discuss the three types of carbohydrate sources. 

1. Starch

Starch is a carbohydrate that is found naturally in plants. These carbohydrate sources take longer to break down, which provide energy for a longer period of time (slow release of energy). This type of carbohydrate is usually consumed as a staple.  Some examples of starch are:

• Vegetables (starchy-type) like potatoes, sweet potatoes, beans, lentils and legumes
• Grains such as oats, barley, rice, products made of flour such as pasta, bread and crackers. 

Whole grains are an example of starches. Each whole grain is composed of three parts. The first two are bran and germ, which contain nutrients and fiber. The third part is the endosperm, which contains the starch. Whole grains as a starch choice provide vitamins, minerals and fiber if unprocessed. Examples are whole-wheat products such as brown rice, whole grain pasta and wheat bread. However, whole grain products may not also be advisable for CKD patients because these products usually contain significant amounts of potassium that may increase complications such as heart problems. 

However, we also have refined grain foods that do not contain bran and germ. When these two are removed, most nutrients and fiber are removed as well. Since potassium content is reduced in refined grain food products, they would, at times, be a better choice for CKD patients.

Since most whole-grain foods are high in potassium and/ or phosphorus, it is commonly advised to choose refined grain products, as they have little potassium and phosphorus content. 

2. Sugar

Sugar is a type of carbohydrate that is widely used in the market. It is commonly used as table sugar, or added sugars for your pastries, beverages and desserts. They give fast-acting energy -- which means they are easily digested and used by the body. 

There are two main sources of sugars: 

Naturally occurring sugars are a better option as they provide fiber and antioxidants that are essential for bodiy function. Meanwhile, products with added sugar contain little to zero nutrients. Excessive intake over a period of time can increase the risk of diabetes and heart disease. 

Meanwhile, products with added sugar contain little to zero nutrients. You may need to be aware of the other name of sugars as you review the ingredients list:

• Table sugar or Sucrose
• Brown Sugar
• Molasses
• Syrup: Maple, High-fructose corn syrup, sugar cane syrup
• Honey
• Beet/Cane sugar
• Raw sugar
• Confectioners or powdered sugar
• Agave nectar

Currently, there are sugar alcohols used in food preparations. Sugar alcohol is a sugar substitute that tastes sweet but has less impact on the blood sugar levels in the body and contributes fewer calories to the body. They’re usually present in “sugar-free” food products and even added in some toothpaste and mouthwash products. Here are a few sugar alcohols you might come across:

• Mannitol
• Sorbitol
• Xylitol
• Lactitol
• Maltitol

What is the downside of too much-refined sugars in your diet?  Since they are easily digested by the body, they can immediately elevate your blood sugar level. Overconsumption of food products high in sugars increases the risk of developing diabetes and other chronic illnesses. 

3. Fiber

The third type of carbohydrate is Fiber. Fiber has two types. First is soluble fiber which can be dissolved in water. This can help lower blood glucose levels and can be found in rolled oats, nuts, beans, lentils, and fruits. On the other hand, insoluble fiber is the second type of fiber which is the indigestible part of a plant. It is insoluble which means it cannot be dissolved by water. It is only found in plants; and common sources are whole grains such as whole-wheat bread, couscous, brown rice, and vegetables. 

Insoluble fiber is very helpful in digestion. It acts like a broom in the gut, where it speeds up digestion and helps sweep our bodies clean of toxic wastes and remove them through a (regular) bowel movement. Consequently, it helps lower cholesterol levels in the body and decreases the chances of developing heart problems. 

According to the 8th Edition of the Dietary Guidelines for American, the recommended dietary intake is 14g per 1,000 calories. On average, for an adult female, the daily fiber intake should be 25 g while for male it is 38 g of fiber. It is better to get fiber from our food choices rather than rely on supplementation. 

Fibrous food choices often contain vitamins and minerals that can help our body function better and maintain our health. However, do not forget to increase your fluid intake or at least maintain 8 to 10 glasses of water a day when eating high fiber products. Eating high fiber foods with little to no water intake may cause constipation. 

So the next time we try to buy bread or any packed food that has a nutrition facts label at the back, try to check the Total Carbohydrates and see which of the three types of carbohydrates are present in your food. 

Serving size of Carbohydrate Food Sources

The serving size of a carbohydrate source may differ per food item. As a reference, here is a list of a few commonly consumed items: 

Bread and Flours

Cereals, Grains, and Pasta

Fruits and Fruit Juices

Note: the weights in parenthesis include the peel, skin, rind, and seeds

Vegetables

 Serving size = 1/2 cup cooked 1 cup raw 1/2 cup vegetable juice  

• Asparagus
• Oriental radish or Daikon
• Baby corn
• Spinach
• Broccoli
• Summer squash

To get a complete copy, you may refer to the food exchange list of the American Dietetic Association.

Disclaimer: The serving size guide is for counselling and monitoring purposes. Carbohydrate requirements may differ per individual which is why guidance from your dietitian is very important. 

How to start your carbohydrate counting

Discussing your food preferences with your dietitian, allow your dietitian to be able to help you distribute your carbohydrates throughout your meals in a day. In this way, your dietitian can help you identify the appropriate serving size of your preferred carbohydrate source. It would also be easier to monitor your carbohydrate intake.

Here's a sample distribution of your carbohydrates:

For example, your dietitian prescription could be a 2,000-calorie diet. Your dietitian will then compute your macronutrient distribution based on your health condition, physical activity, and weight. This is how he/she may compute it:

• Carbohydrates: 50% of 2,000 calories = 1,000 calories

Then divide into 4 g of carbohydrates to get total carbohydrate requirement in grams: 250 g of carbohydrates

• Protein: 15% of 2,000 calories = 300 calories

Then divide into 4 g of carbohydrates to get total protein requirement in grams: 75 g of protein

• Fat: 35% of 2,000 calories = 700 calories

Then divide into 9 g of fats to get total fat requirement in grams: 77 g of fat

FINAL MACRONUTRIENT DISTRIBUTION:

250g Carbohydrates, 75g Protein, 77g Fat 

Meal
Breakfast 60 g
Mid-morning snack 30 g
Lunch 60 g
Mid-afternoon snack 25 g
Dinner 60 g
Bedtime snack 15 g

Total Carbohydrates: 250g

Using the sample serving sizes stated above, your carbohydrate choices can be like this: 

MEAL: Breakfast

MEAL: Mid-morning snack

MEAL: Lunch

MEAL: Mid-afternoon snack

MEAL: Dinner

MEAL: Bedtime snack

Total Carbohydrates: 250g

Carbohydrate sources to watch out for in your diet

Unfortunately, not all carbohydrate sources are suitable for a Kidney-friendly Diet. This is mainly due to the high potassium and phosphorus content of some food items. Since these (food) items are commonly available in the market, you should be aware of them. 

Some well-known carbohydrate sources that are high in potassium and/or phosphorus are:

• Bananas
• Brown Rice
• Whole wheat grains and cereals
• Chocolate containing carb sources
• Beans, peas, and lentils
• Pumpkin 
• Potatoes
• Orange and orange juice

You can opt for these alternatives:

Summary

Here are a few tips to remember when you decide to carb count:

• Do your research and read the notes that your dietitian will give you. 
• Your kidney condition will also help determine your carbohydrate requirement per day. 
• Choose carbohydrate sources that have low potassium and phosphorus content levels
• Carbohydrate servings may vary per food item. If you have difficulties identifying a portion size, don't be afraid to check the food exchange list. 
• Don't be afraid to get creative with your meals. Work with your dietitian to achieve an individualized meal plan catered to meet your preferences.

Carbohydrate counting for CKD may be challenging at first, but with proper guidance from your doctor and dietitian, you will adapt to it in no time.