The Myth That Keto Damages Your Kidneys
The ketogenic diet is often misunderstood, with one persistent claim being that it causes kidney damage. This stems from outdated assumptions about protein metabolism rather than contemporary evidence. Multiple studies have found no adverse renal effects in healthy individuals following well-formulated low-carbohydrate diets.
How the myth originated
Early concerns about kidney stress came from extrapolating studies of people with pre-existing kidney disease to the general population. High-protein diets were thought to increase glomerular filtration rate (GFR), interpreted as “overworking” the kidneys. However, increased GFR is a normal adaptive response to higher protein intake, not a sign of damage. the difference between dietary and endogenous ketones plays a key role in this misunderstanding.
What the research shows
A 2018 review in Nutrients analysed 13 studies involving over 2,000 participants without kidney disease. It found no clinically significant changes in kidney function markers like serum creatinine or GFR among those following ketogenic diets for up to two years (Kosinski & Jornayvaz, 2017). The authors noted that concerns were largely theoretical rather than evidence-based.
For people with type 2 diabetes – a population at higher risk of kidney issues – research actually shows improvement in renal markers. The Virta Health study demonstrated stabilised kidney function in participants following a medically supervised ketogenic diet for two years (Athinarayanan et al., 2019).
What this means in practice
UK adults considering keto needn’t fear kidney damage if they’re otherwise healthy. Practical steps:
- Stay hydrated, especially during the initial adaptation phase when water loss increases
- Include electrolyte-rich foods like leafy greens and avocados (£1.20 for a pack of three at Tesco)
- Moderate protein intake to 1.2-1.7g per kg of body weight unless strength training
- Those with existing kidney conditions should consult their GP before dietary changes
managing keto flu symptoms often addresses the temporary electrolyte imbalances some mistake for kidney stress.
Frequently asked questions
Does keto cause kidney stones?
No increased risk has been found in studies of well-formulated ketogenic diets. The myth may come from early epilepsy treatment diets that were very low in fluids. Modern keto emphasises hydration and includes citrate-rich foods like lemons that may actually protect against stones.
Should I worry about protein on keto?
Unless you have pre-existing kidney disease, moderate protein intake poses no risk. The average UK keto diet contains less protein than many assume – around 15-20% of calories, similar to traditional diets. Excess comes from misunderstanding bodybuilding protocols as standard keto practice.
Are there any real kidney risks with keto?
Only for those with advanced chronic kidney disease (CKD), who require medical supervision for any dietary change. For healthy individuals, multiple studies show preserved kidney function. Those with stage 1-2 CKD may actually benefit from keto’s blood sugar control effects.
The bottom line
Current evidence clearly refutes the idea that ketogenic diets damage healthy kidneys. Concerns stem from misapplied research and outdated assumptions about protein metabolism. With proper hydration and electrolyte management – standard advice for any dietary approach – keto appears neutral or potentially beneficial for renal function in most people. If you’d rather not do the macro maths yourself, the Keto Dieting app does it for you on Google Play and the App Store.
References
- Kosinski C, Jornayvaz FR (2017). Effects of Ketogenic Diets on Cardiovascular Risk Factors: Evidence from Animal and Human Studies. Nutrients. https://doi.org/10.3390/nu9050517
- Athinarayanan SJ, Adams RN, Hallberg SJ, et al. (2019). Long-Term Effects of a Novel Continuous Remote Care Intervention Including Nutritional Ketosis for the Management of Type 2 Diabetes: A 2-Year Non-randomized Clinical Trial. Frontiers in Endocrinology. https://doi.org/10.3389/fendo.2019.00348
