Keto and Kidney Stones in Men: What the Evidence Shows

The ketogenic diet has gained attention for its potential metabolic benefits, but concerns persist about its impact on kidney health, particularly regarding kidney stones in men. While the diet restricts carbohydrates to induce ketosis, its higher protein content and diuretic effect raise valid questions about urinary mineral excretion.

How Ketosis Affects Kidney Chemistry

Ketosis alters several urinary markers. A 2013 study found that very-low-carbohydrate diets increase urinary calcium excretion by approximately 60 mg per day compared to low-fat diets (Bueno et al., 2013). For men predisposed to calcium oxalate stones—the most common type—this warrants attention. The same study noted no significant changes in urinary oxalate, citrate, or uric acid levels when adequate hydration was maintained.

keto electrolyte supplementation becomes crucial here. Sodium, potassium, and magnesium losses through urine increase during ketosis, potentially creating imbalances that affect stone formation. A 500 ml bottle of Buxton mineral water containing 38 mg of magnesium costs £1.20 at Tesco, offering a convenient hydration option.

Practical Risk Reduction Strategies

What This Means in Practice

Three adjustments significantly lower stone risk without abandoning ketosis: 1. Increase fluid intake to 2.5-3 litres daily (evidenced by a 20-40% reduction in stone recurrence in general populations) 2. Consume 100-150g of leafy greens like spinach or kale (£0.80 per 200g bag at Aldi) for alkaline minerals 3. Add 30ml lemon juice daily—its citrate binds to calcium before stones can form

managing gout on keto shares similar hydration principles. Both conditions respond to controlled pH and mineral balance.

Frequently Asked Questions

Does keto cause kidney stones in all men?

No. Genetic predisposition plays the largest role. Those with a personal or family history of stones should monitor hydration and urinary pH more carefully.

How quickly can stones form on keto?

In susceptible individuals, symptomatic stones may develop within 3-6 months if hydration and electrolytes aren’t addressed. Annual kidney ultrasound screening provides early detection.

Are protein shakes risky?

Whey protein isolate increases urinary calcium less than concentrates. Limit to 30g per serving and always pair with 250ml water.

The Bottom Line

The ketogenic diet doesn’t inherently cause kidney stones but may accelerate their formation in predisposed men through increased calcium excretion and concentrated urine. Strategic hydration, mineral-rich foods, and citrate sources like lemon juice create protective factors. 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.

Educational only — not medical advice. This article is for general information. Speak to your GP before changing your diet, especially if you have type 1 or type 2 diabetes, kidney or liver disease, are pregnant or breastfeeding, or take medication for blood pressure, cholesterol, or blood glucose.

References

Bueno NB, de Melo IS, de Oliveira SL, da Rocha Ataide T (2013). Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: a meta-analysis of randomised controlled trials. British Journal of Nutrition. https://doi.org/10.1017/S0007114513000548
Hyde PN, Sapper TN, Crabtree CD, et al. (2019). Dietary carbohydrate restriction improves metabolic syndrome independent of weight loss. JCI Insight. https://doi.org/10.1172/jci.insight.128308