Carbohydrates often get a bad reputation, but they are an important source of energy for our bodies. Let’s break down the different types of carbs, their role in our diet, and how to choose the best options when planning meals for PKD.

Types of Carbohydrates

There are three main types of carbohydrates:

1. Sugars: These are simple carbs found in foods like fruits (fructose) and table sugar (sucrose). They provide quick energy, but too much can cause weight gain, high blood sugar, or cholesterol.
2. Starches: These are complex carbs made of long chains of sugar molecules. They are found in foods like grains, beans, and vegetables. They give you energy more slowly because your body takes longer to break them down.
3. Fibre: This type of carb isn’t digested, but it helps with digestive health, lowers cholesterol, and keeps your blood sugar steady. Fibre is found in fruits, vegetables, whole grains, nuts, and seeds.

The Role of Carbs in our Diet

Carbohydrates do a lot for our bodies:

• Energy: They’re the body’s preferred source of energy, especially for your brain and muscles during physical activity.
• Nutrients: Foods with healthy carbs, like whole grains, fruits, and vegetables, are full of vitamins, minerals and antioxidants.
• Digestive Health: Fibre helps with digestion, prevents constipation, and keeps your gut healthy.

Not all carbs are the same. Aim for carbs that are higher in fibre, and follow these guidelines:

• Choose carbs found in whole, unprocessed foods like fruits, vegetables, beans, and whole grains. These carbs are typically high in fibre and nutrients, leading to better overall health. Examples are oatmeal, barley, and whole-grain bread.
• Limit carbs from highly processed foods with added sugar and unhealthy fats, like sugary snacks, baked goods, and pop or juice.

The Keto Diet and PKD 

The ketogenic (keto) diet has become popular for weight loss and other health benefits, but studies have also shown some consequences to this diet. If you have PKD, dietary choices can be more complex, and the research about keto and PKD is still new.

What is a Keto Diet? 

The keto diet is high in fat and very low in carbs. It helps the body burn fat for energy instead of carbs, a state called ketosis. A typical keto diet includes about 70-75% fat, 20-25% protein, and only 5-10% carbohydrates, although these macronutrient ratios can vary.

Potential Benefits of Keto for PKD Patients:

1. Weight Management: Keeping a healthy weight is important for PKD patients because obesity can make kidney problems worse, and increase the size of the kidneys. The keto diet might help with weight loss and maintaining a healthy weight.
2. Blood Sugar Control: Some studies show that the keto diet can improve insulin sensitivity and lower blood sugar, which could help people with PKD – especially if they have diabetes, or are at risk for diabetes. However, this hasn’t been proven in PKD studies yet.
3. Possible Reduction in Kidney Volume: Early research suggests the keto diet may reduce kidney size, but the studies are small and short-term.

Considerations and Risks

If you have PKD and are thinking about trying the keto diet, here are some things to be cautious about:

1. Kidney Health: The high protein in some keto diets can strain your kidneys, so you’ll need to monitor your kidney function closely with your healthcare provider.
2. Fats: The diet can include unhealthy fats, like saturated and trans fats, which can raise the risk of heart disease. Plan well to make sure your fat choices are healthy, and your nutrition needs are met.
3. Sustainability: Diets like keto can be hard to stick with over time. It’s better to find a balanced eating plan you can follow for many years, to help your health, manage your PKD, and prevent complications.
4. Everyone is Different: Each person reacts differently to diet changes, so what works for one person may not work for another. People with PKD are at higher risk for kidney stones, liver cysts, and heart disease, which may be made worse by the keto diet.

What Should I Eat If I Have PKD?

The keto diet might help some people with PKD, but you should be careful. Instead of cutting out carbs completely, choose healthier options:

1. Talk to your registered dietitian or nephrologist to understand how much and how often to eat carbs, and see if a keto diet is right for you.
2. If you eat carbs, choose whole grains like brown rice, quinoa, and whole wheat pasta over refined carbs.
3. Watch your portion sizes, especially for grains and starchy vegetables. Keep carbs to about 1/4 of your plate.
4. Limit added sugars, like those in sweets and sugary drinks. Read labels to spot hidden sugars.
5. Load up on fruits and vegetables. Aim for a variety of colours to get a range of nutrients. Fresh, frozen, or dried (without added sugar) options are all good.
6. Include legumes (beans, lentils, chickpeas) in your diet. They’re high in fibre, protein, and important nutrients. When you have PKD, the kind of protein you choose is important.

Before making big changes to your diet, speak with your healthcare team or a registered dietitian to create a plan that supports your kidney health. Everyone with PKD has different needs, so a personalized approach that takes into account your health, activity, food preferences, and lab tests is best.

About the author: Emily Campbell, RD CDE MScFN is a Registered Dietitian and Certified Diabetes Educator with a Master’s Degree in Foods and Nutrition. Emily specializes in helping those with kidney disease overcome the confusing world of nutrition to promote health. Emily and her team of dietitians can be found at kidneynutrition.ca.

More

• Looking for more information about what to eat with PKD? Check out Love Your Kidneys, a PKD cookbook and nutrition guide written especially for people with PKD.
• Watch one of Emily's webinar or PKD Summit recordings on the topic of Nutrition and PKD, here or here.
• Browse through Emily's Kidney Nutrition blogs on our website, here.