# Your kidneys fail quietly. Blood sugar and blood pressure do most of the damage. > Diabetes and high blood pressure cause most kidney failure. Get the two kidney tests (eGFR and urine albumin), bring blood sugar and blood pressure down, move daily, avoid anti-inflammatory painkillers, and retest. If you already have kidney disease, fasting, supplements and diet changes need your doctor’s sign-off first. - URL: https://www.plansforyourbody.com/plans/protect-your-kidneys/ - Categories: Heart & circulation - Updated: 2026-10-06 - Not medical advice: Discuss everything here with a medical doctor before acting on it — supplements included. Your doctor has your bloodwork and history. We have neither. ## The goal You can lose more than half your kidney function before you feel a thing. By the time you do, the options are shorter. Two cheap tests catch it early, and the two biggest causes, blood sugar and blood pressure, are things you can move. This plan gets the tests done, works on the causes, and is honest about what needs a nephrologist. - **Measure:** eGFR · urine ACR · HbA1c · home blood pressure · medication review - **Change:** Lower blood sugar and insulin · lower blood pressure · less processed salt · move · no NSAIDs - **Retest:** At 3–6 months, then on the schedule your stage needs ## Why it matters: One in ten Canadians. Most don’t know. - **The default:** Nobody orders the urine test, the creatinine creeps up a little each year, and “your kidneys are a bit sluggish” turns into a referral, then dialysis. Kidney disease also multiplies your risk of heart attack and stroke long before the kidneys fail. - **The better bet:** The Kidney Foundation of Canada counts diabetes as the leading cause of kidney failure, at 38%. High blood pressure is the other big one. Both respond to the same root-cause work: lower insulin and blood sugar, lower pressure, less visceral fat. That’s Jason Fung’s argument as a nephrologist: treat the diabetes, and you protect the kidney. It slows damage for many people; it doesn’t guarantee the kidneys won’t decline. ## How it works: A million tiny filters, under too much pressure. Each kidney holds about a million filtering units. High blood sugar and high blood pressure force them to filter under strain. Over years they scar and drop out, and the ones left work harder, which wears them out faster. Albumin leaking into the urine is the early sign that the filters are being damaged. - **eGFR:** How much blood your kidneys filter per minute, estimated from a creatinine blood test. 90 or more is normal; under 60 for three months or more is chronic kidney disease. Muscle mass skews creatinine. The 2024 KDIGO guideline, co-chaired by Canadian nephrologist Adeera Levin, now recommends adding a cystatin C test when it’s available, to get a more accurate number. - **Urine ACR:** Albumin-to-creatinine ratio, from a single urine sample. The earliest warning: it can rise years before eGFR falls. Under 3 mg/mmol (30 mg/g) is normal; 3–30 is moderately raised; over 30 is severely raised. - **Stage:** KDIGO stages CKD by both numbers: G1–G5 for eGFR and A1–A3 for albumin. Both matter. A normal eGFR with high albumin is still kidney disease. The 2024 guideline asks doctors to check both, because together they give a truer picture of risk than either alone. - **Blood sugar and insulin:** High glucose damages the filters directly. Insulin resistance also raises blood pressure and makes the kidneys hold salt and water. - **Blood pressure:** Both a cause and a result: damaged kidneys raise pressure, and high pressure damages kidneys. Breaking that loop is the core of treatment. - **Uric acid:** Often high in kidney disease. Richard Johnson argues fructose and uric acid help drive it; trials of urate-lowering drugs disagree (see below). ## The steps: Get the two tests. Lower sugar and pressure. Protect what’s left. ### If you have kidney disease (Read first): Your doctor signs off before you change the big things. - **Fasting** (doctor’s approval first): Fasting shifts fluids and electrolytes and changes how some drugs behave, especially diuretics, blood pressure pills and diabetes medication. With kidney disease, don’t fast without your doctor’s explicit OK. - **Supplements and herbal products** (doctor’s approval first): Damaged kidneys clear things slowly. Magnesium, potassium, potassium-based salt substitutes, creatine, high-dose vitamins and many herbal products can build up. Show your doctor or pharmacist everything you take. - **Protein** (follow your nephrologist): KDIGO suggests about 0.8 g per kg of body weight a day in CKD stages 3–5 not on dialysis. Don’t start a high-protein or very low-protein diet on your own. - **Sick days** (ask for a plan): Vomiting, diarrhoea or not drinking enough can injure kidneys fast on some medications. Ask your doctor which pills to pause when you’re sick, and never stop anything without that plan. ### Measure (Week 0): Two tests most people never get. - **eGFR** (creatinine blood test): Usually on routine bloodwork. Ask for the number, not just “fine”. If you’re very muscular, very lean or the result is borderline, ask whether a cystatin C test is available; KDIGO 2024 recommends it for a more accurate estimate. - **Urine ACR** (ask for it): A single urine sample, ideally first thing in the morning. Diabetes Canada recommends it at diagnosis of type 2 diabetes and yearly after. If you have high blood pressure, ask for it too. A high result needs repeating within 3 months to confirm. - **HbA1c** (three-month blood sugar): The single biggest lever on diabetic kidney disease. - **Fasting insulin and glucose** (morning, after an overnight fast): Together they give HOMA-IR, a simple insulin-resistance score. Fasting insulin often isn’t covered in Canada. It’s cheap to pay for. Insulin resistance raises blood pressure and kidney strain years before blood sugar looks abnormal. - **Home blood pressure** (7 days, done properly): Upper-arm cuff, morning and evening, averaged. The blood pressure plan has the method. - **Medication review** (with your pharmacist): List everything: prescriptions, painkillers, supplements, herbal products. Some need lower doses as kidney function falls. ### Change the inputs (Months 1–6): Lower sugar and pressure. Stop the avoidable damage. - **Sugar and refined carbs** (cut hard): Sugar, sweet drinks, juice, white flour and most packaged snacks. The fastest lever on insulin, blood sugar and triglycerides. Lower blood sugar means less damage to the filters, and lower insulin means less salt and water retention. - **Real food** (protein first): Build meals on protein, vegetables and natural fats: fish, meat, eggs, dairy, legumes, nuts. Protein and fibre keep you full and flatten glucose spikes. With kidney disease, ask your doctor or a renal dietitian how much protein is right for your stage. - **Processed-food salt** (under 2 g sodium a day): KDIGO’s target for people with CKD. Most of it comes from bread, deli meat, sauces, soups and takeout, not the shaker. Cooking real food does most of the work. - **Eating window** (daily, e.g. noon to 8 pm): Eat inside a fixed window and not outside it. Fewer insulin spikes per day, fewer chances to overeat. Only if your doctor agrees, if you have kidney disease or take diabetes medication. - **Move daily** (150+ min/week): KDIGO recommends at least 150 minutes a week of moderate activity, or as much as your heart and body tolerate. Walking counts. Add strength work to keep the muscle that goes first in kidney disease. - **Sleep** (7+ hours): One short night measurably worsens insulin sensitivity, blood sugar and appetite the next day. The cheapest part of the protocol, and the most skipped. - **No NSAIDs** (ibuprofen, naproxen): Anti-inflammatory painkillers cut blood flow to the kidneys. With kidney disease, avoid them. Ask your pharmacist what to use instead. - **Stop smoking** (kidneys too): Smoking damages small blood vessels, in the kidneys as well as the heart, and kidney disease already raises heart risk. Quitting cuts the heart risk smoking adds, fastest in the first few years, though it stays above a never-smoker’s for years. Ask your doctor for help quitting. - **Alcohol** (none while fixing the numbers): It goes straight to the liver, raises triglycerides and adds to liver fat. Less is better; none is best while you’re fixing the numbers. It raises blood pressure. Less is better. **Before you fast:** Don’t do extended fasts if you’re on insulin or other diabetes medication, pregnant, breastfeeding, underweight, or have a history of eating disorders, unless your doctor approves. ### With your doctor (Once you have your numbers): Kidney protection now comes in pills, too. - **Blood pressure target** (ask your doctor): KDIGO suggests a systolic target under 120 mmHg in CKD, when tolerated and measured in a standardised way. Ask what your target is. - **Kidney-protecting medication** (ask your doctor): If you have albumin in your urine or diabetes, ask your doctor about ACE inhibitors or ARBs and SGLT2 inhibitors. KDIGO and Diabetes Canada both recommend them for many people with CKD. In Hiddo Heerspink’s DAPA-CKD trial of 4,304 people with CKD and albumin in the urine, an SGLT2 inhibitor lowered the combined risk of major kidney decline, kidney failure or death by about 39%, with or without diabetes. This isn’t instead of the lifestyle work; it’s alongside it. - **Heart risk** (ask your doctor): Kidney disease raises heart-attack risk. KDIGO recommends statins for many adults with CKD. Ask whether you’re one of them. ### Retest (Months 3–6): Watch the slope, not one number. - **eGFR and ACR** (same lab if you can): eGFR wobbles with hydration, meat intake and exercise. One drop isn’t a trend; three readings in a row are. Falling ACR is good news. - **HbA1c and blood pressure** (the drivers): If these improved, your kidneys are under less strain, whatever this month’s eGFR says. - **If the numbers won’t move** (your doctor): Take the before-and-after numbers to your doctor. Whether you need medication is their call. Needing it isn’t failure. eGFR falling fast, ACR above 30 mg/mmol, or potassium out of range: ask for a nephrology referral. ## The rules: Short list. No exceptions. **Choose:** - Real food you cook, so you control the salt - Water as your drink - Walking daily, and strength work twice a week - A pharmacist check before any new pill or supplement **Avoid:** - Ibuprofen, naproxen and other NSAIDs - Sugar, sweet drinks and refined carbs - Processed meat, packaged snacks and takeout - Supplements and herbal products your doctor hasn’t approved **Non-negotiables:** - Know your eGFR and your urine ACR. - With kidney disease, no fasting and no supplements without your doctor’s sign-off. - Never stop a prescribed medication on your own. - Swelling, very little urine, or confusion with a known kidney problem: see a doctor today. ## Checkpoints: What to track, and what good looks like. Your doctor sets your targets by stage. These are the KDIGO reference points. | What | Target | How and when | |---|---|---| | eGFR | ≥90 normal; stable, not falling | Blood test, every 3–12 months depending on stage. Under 60 for 3+ months is CKD. | | Urine ACR | <3 mg/mmol (30 mg/g) | Single urine sample. Diabetes Canada flags 2 mg/mmol and above on repeat testing. | | Blood pressure | Systolic <120 in CKD if tolerated (KDIGO) · home <135/85 otherwise (Canada) | Home log plus standardised office readings. | | HbA1c | Usually ≤7.0% with diabetes; <6.0% without | Every 3–6 months. Your doctor individualises the target. | | Sodium | <2 g a day with CKD | Read labels for a week. You’ll find most of it in packages. | | Waist-to-height | <0.5 | Monthly, at the belly button. | eGFR estimates, it doesn’t measure. A big muscular person can read low; someone very frail can read falsely reassuring. Watch the trend. ## Where experts disagree: Where the experts don’t agree. Everyone agrees on blood sugar, blood pressure and no NSAIDs. The arguments are about protein, uric acid and fasting. ### Is a high-protein diet bad for your kidneys? - **No, if they’re healthy: Phillips, Devries (McMaster):** A 2018 meta-analysis of 28 studies found higher-protein diets did not change kidney function in healthy adults, including people at risk from obesity, high blood pressure or type 2 diabetes. - **Careful with CKD: KDIGO 2024:** In CKD stages 3–5 not on dialysis, aim for about 0.8 g/kg/day, the general-population allowance. Damaged kidneys may not handle the extra filtering load. **Our read:** Healthy kidneys: eat enough protein to keep your muscle. Known CKD: your nephrologist decides, and the evidence there is weak, so ask why. ### Does lowering uric acid protect the kidneys? - **Uric acid matters: Richard Johnson:** Fructose raises uric acid, and uric acid injures blood vessels and kidneys. High uric acid predicts kidney disease, and cutting fructose lowers it. - **Trials say no: CKD-FIX (Badve) and PERL investigators:** In two 2020 NEJM trials, allopurinol lowered uric acid but did not slow the decline in kidney function. **Our read:** A pill that lowers uric acid didn’t save kidneys. Cutting sugar is still worth it: it lowers blood sugar, insulin and blood pressure too. Do it for those. ### Can fasting help kidneys? - **Treat the cause: Fung:** Type 2 diabetes is the leading cause of kidney failure, and fasting and cutting refined carbs can put it into remission for some people. Remove the cause, and you protect the kidney. - **Careful with CKD: most nephrologists:** Fasting with established kidney disease risks dehydration, electrolyte problems and medication complications. Benefits are unproven there. **Our read:** Before kidney disease, fixing insulin is among the best protection you have. With kidney disease, any fasting is supervised or not done. ### Lifestyle or pills first? - **Root cause first: Fung:** Most kidney failure comes from type 2 diabetes and high blood pressure. Lower insulin, blood sugar and pressure with food and fasting, and you remove much of the strain on the filters. - **Proven drugs early: Heerspink, KDIGO 2024 (Levin, Stevens):** In trials like DAPA-CKD, kidney-protecting drugs slowed decline even in people without diabetes, on top of usual care. Waiting to see if lifestyle works costs filters you can’t get back. **Our read:** Not either-or. Do the root-cause work, and if you have albumin in your urine or a falling eGFR, ask about the drugs now. Lost filters don’t regrow, so this isn’t the place to wait and see. ## Limits: What no plan fixes. - **Lost filters:** Scarred kidney tissue doesn’t regrow. The plan slows the loss; it doesn’t reverse years of damage. Advanced CKD is a nephrologist’s job. - **Other causes:** Polycystic kidney disease, glomerulonephritis, blockages, some medications and inherited conditions don’t come from blood sugar or pressure. If yours doesn’t fit the usual story, ask your doctor why. - **Age:** eGFR drifts down with age. A slow drift is normal; a fast drop isn’t. Your doctor reads the difference. *The plan protects what you have. Your nephrologist manages what’s already lost.* ## Resources - The Diabetes Code — Jason Fung, MD. A nephrologist’s case for treating type 2 diabetes with diet and fasting, the main cause of kidney failure. - [Key takeaways from the KDIGO 2024 CKD guideline, for people living with CKD](https://kdigo.org/wp-content/uploads/2025/01/Key-Takeaways_KDIGO-2024-CKD-Guideline_People-Living-with-CKD.pdf) — KDIGO. The international guideline, in plain language for patients. - [Chronic kidney disease in diabetes](https://www.diabetes.ca/chapter-29-2025-update) — Diabetes Canada. What your Canadian doctor works from if you have diabetes. ## Questions ### What are the early signs of kidney disease? Usually none. You can lose more than half your function without symptoms. The only reliable early signs are on tests: albumin in the urine (ACR) and a falling eGFR. ### What is a normal eGFR? 90 or more is normal. 60–89 can be normal with age if there’s no albumin in the urine. Under 60 for three months or more is chronic kidney disease. ### Can kidney function improve? eGFR can rise a little when blood sugar and blood pressure improve, and albumin in the urine often falls. Scarred tissue doesn’t regrow, so the realistic goal is to slow or stop the decline. Results vary. ### Do SGLT2 inhibitors only help people with diabetes? No. In the DAPA-CKD trial, the kidney benefit was similar with or without type 2 diabetes. Whether one is right for you is a conversation with your doctor. ### Is high protein bad for your kidneys? Not for healthy kidneys, according to a 2018 meta-analysis. With CKD stages 3–5, KDIGO suggests about 0.8 g/kg/day. Ask your doctor before changing it. ### Which painkillers are safe for kidneys? Avoid ibuprofen, naproxen and other NSAIDs if you have kidney disease. Ask your pharmacist what fits your situation. ### Should I drink more water? Drink to thirst and enough that your urine is pale. More isn’t always better, and with advanced CKD or heart failure your doctor may limit fluids. ## Sources - Jason Fung, MD — Nephrologist, Toronto. Author of The Diabetes Code and The Obesity Code. - Adeera Levin, MD — Nephrologist, University of British Columbia. Co-chair of the KDIGO 2024 CKD guideline. - Hiddo Heerspink, PhD — Clinical pharmacologist, University Medical Center Groningen. Lead author of the DAPA-CKD trial. - Richard J. Johnson, MD — Nephrologist, University of Colorado. Research on fructose, uric acid and kidney disease. - Stuart Phillips, PhD — Kinesiologist, McMaster University. Protein and muscle research. - Sunil Badve, MD — Nephrologist, The George Institute. Led the CKD-FIX trial. 1. [KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease](https://pubmed.ncbi.nlm.nih.gov/38490803/). Kidney International, 2024. 2. [Blood pressure management in chronic kidney disease: KDIGO guideline, ten points to remember](https://www.acc.org/latest-in-cardiology/ten-points-to-remember/2021/06/28/17/13/management-of-blood-pressure-in-ckd). American College of Cardiology, 2021. 3. [Chronic kidney disease in diabetes (Chapter 29, 2025 update)](https://www.diabetes.ca/chapter-29-2025-update). Diabetes Canada, 2025. 4. [Facing the Facts 2022](https://kidney.ca/KFOC/media/images/PDFs/Facing-the-Facts-2022.pdf). Kidney Foundation of Canada, 2022. 5. [Myth busted: researchers show that a high-protein diet does not affect kidney function (Devries et al., J Nutr 2018)](https://news.mcmaster.ca/myth-busted-researchers-show-that-a-high-protein-diet-does-not-affect-kidney-function/). McMaster University, 2018. 6. [Frequently prescribed allopurinol no better than placebo for CKD in head-to-head trial (CKD-FIX)](https://ajmc.com/view/frequently-prescribed-allopurinol-no-better-than-placebo-for-ckd-in-headtohead-trial). AJMC, 2020. 7. [KDIGO releases updated clinical practice guideline for CKD evaluation, management](https://www.healio.com/news/nephrology/20240313/kdigo-releases-updated-clinical-practice-guideline-for-ckd-evaluation-management). Healio, 2024. 8. [Dapagliflozin in patients with chronic kidney disease (DAPA-CKD)](https://doi.org/10.1056/NEJMoa2024816). New England Journal of Medicine, 2020. 9. [Key takeaways: KDIGO 2024 CKD guideline for people living with CKD](https://kdigo.org/wp-content/uploads/2025/01/Key-Takeaways_KDIGO-2024-CKD-Guideline_People-Living-with-CKD.pdf). KDIGO, 2025.