The SCVC Blog

Cardiovascular care news and articles from our expert team

Can You Go Low-Carb with Kidney Disease? A Safer Way to Improve Blood Sugar Without Harming Your Kidneys

Posted on Tuesday September 16, 2025 in Glucose and Insulin Dynamics

An article written by Dr Edward Leatham, Consultant Cardiologist

For many people with high blood pressure, type 2 diabetes, or excess weight around the middle, a low-carbohydrate diet with higher protein intake can be a powerful tool. It improves blood sugar, reduces insulin resistance, lowers blood pressure, and helps with weight loss.

But what if you’ve also been told you have chronic kidney disease (CKD), stage 3b?

At SCVC, we’re often asked:

“Can I still do low-carb safely with reduced kidney function?”
“Will it damage my kidneys if I increase protein?”
“Is this even an option for me?”

The short answer: Yes—with a few important modifications.

We’ve created a new one-page patient guide to help you follow a renal-safe version of the low-carb diet, designed specifically for people with stage 3b CKD (when your eGFR is between 30 and 44).

👇 Download the SCVC Renal-Safe Low-Carb Diet Guide (PDF)

🔍 Why low-carb?

Low-carb eating reduces the amount of sugar (glucose) entering your bloodstream. It can:

Lower HbA1c and reduce the need for diabetes medication
Improve insulin sensitivity (especially important for belly fat and prediabetes)
Help lower triglycerides and raise HDL cholesterol
Support weight loss, especially around the waist
Reduce blood pressure, sometimes allowing fewer tablets

All of these are great for kidney health too—when done right.

⚠️ But isn’t protein a problem in kidney disease?

Yes and no.

While very high protein diets can strain the kidneys and accelerate decline in CKD, moderate protein intake—around 0.8 grams per kg of ideal body weight per day—is safe and recommended by international guidelines¹.

That’s the key difference in our renal-safe approach:

It’s low-carb (to improve blood sugar and weight)
But not high-protein (to protect kidney function)
And uses healthy fats (to support heart and metabolic health)

✅ What foods can I eat?

Here’s a taste of what’s inside the guide:

✔ Best Protein Sources:

Tofu, lentils, chickpeas, small portions of fish or skinless chicken
Eggs (1 per day), soy milk, quinoa
Limit red meat and processed meats

✔ Best Carbs:

Leafy greens, cauliflower, broccoli, courgette
Berries, apples (in portions)
Chia, flaxseed, small portions of oats

✔ Best Fats:

Olive oil, avocado, nuts, seeds, oily fish (like salmon)
Avoid excess butter, cream, and coconut oil

The guide also includes a lab monitoring checklist and reminder to work closely with your renal and diabetes team.

🧪 What should I monitor?

If you’re switching to a lower-carb way of eating, especially with CKD, we recommend checking the following every 3–4 months:

eGFR (on a fasting day without meat to avoid false dips)
UACR (urine protein)
Potassium and bicarbonate (to avoid acidosis or high potassium)
Lipids and uric acid (especially if eating more fat or losing weight)
Weight, blood pressure, and waist size

These help you and your clinician keep your kidneys and heart on track.

🎯 Final Thoughts

You don’t have to choose between kidney health and metabolic control. With the right dietary tweaks and support, a renal-safe low-carb diet can offer the best of both worlds—helping you improve your blood sugar, weight, and blood pressure without accelerating kidney decline.

🧾 Click here to download the SCVC Renal-Safe Low-Carb Diet Guide (PDF)

If you have stage 3 CKD and are thinking about a diet change, speak with your SCVC renal consultant or dietitian to tailor your plan safely.

🧠 References

KDIGO 2020 Clinical Practice Guideline for Nutrition in CKD. Kidney Int Suppl. 2020;98(4S):S1–S130.
Does a High-Protein Diet Accelerate CKD Progression in Stage 3b?

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