There are many ways to eat well – from lower-carb and Mediterranean to DASH, plant-based, low-fat and, yes, even ketogenic (keto). These are called dietary patterns: broad “templates” for how you put meals together day-to-day.
However, if you’re living with chronic kidney disease (CKD), you may be wondering whether all of these are appropriate, and let’s face it, the internet can feel like a maze. One site says “go keto,” another warns against it. Protein targets, potassium, phosphate, carbohydrate counting… It’s a lot – especially when you just want to know what’s safe for your kidneys and realistic for your life.
As kidney dietitians, we hear this confusion all the time. It’s completely understandable – nutrition headlines can be scary, and CKD just adds an extra layer to think about.
Our promise in this guide: we’ll provide a clear, balanced, practical look at keto diets and CKD – where it may help, where it may harm, and which alternatives often work better long-term.
Let’s make sense of it – step by step.
Let’s talk macros
If you’ve heard friends talk about “going keto” or “cutting the carbs,” it can sound tempting -but what do these terms actually mean, and how might they fit (or not) for someone with CKD? Let’s start with clear definitions in plain English.
First things first: let’s discuss “macros”.
“Macros” (short for macronutrients) are the three main sources of calories in food:
- Carbohydrate: found in foods like bread, rice, pasta, fruit, beans and vegetables.
- Protein: found in foods like meat, fish, eggs, dairy, tofu/tempeh, beans/pulses and meat alternatives.
- Fat: found in foods like oils, butter, nuts, seeds, avocado, olives and spreads.
Different eating patterns adjust the proportion of calories coming from each macro.
What is a keto diet?
A ketogenic diet is a very low-carbohydrate, moderate/high protein, high-fat diet. This shifts the body’s main energy source from glucose/sugar (from carbs) to ketones (from fat), known as ketosis. Typical targets are:
- Carbohydrate: 5–10% of total calories (often 20–50 g carbs per day). As an example, a slice of bread can have between 9-19g of carbs.
- Protein: 25-30% of total calories
- Fat: 60-65% of total calories
In practice, that means limiting foods such as bread, rice, pasta, potatoes, most grains, many fruits, and many snack foods. Meals are built mainly around foods high in fats and protein.
A keto plate might include salmon or tofu, a generous olive oil-dressed salad, roasted non-starchy vegetables (e.g., courgette, peppers), and avocado – while skipping potatoes, bread, or rice.
What is a low-carb diet?
A low-carb diet is a broader, less strict diet. It generally means fewer carbs than a typical diet, without necessarily entering ketosis. Typical targets are:
- Carbohydrate: roughly 10–25% of calories (often 50–130 g/day depending on energy needs. 50g of carbs is roughly 2 slices of bread or a large baked potato).
- Fat and protein: make up the remainder in flexible proportions.
A low-carb plate might be chicken or chickpea salad with olive oil, extra veg, a small portion of quinoa or new potatoes, and berries for pudding.
What is a plant-based keto diet?
A plant-based keto approach keeps carbs very low, like the traditional keto diet, while prioritising plant fats and plant proteins. It typically features:
- Carbohydrates: small portions of pulses & vegetables
- Fats: olive oil, rapeseed oil, avocado, olives, nuts, seeds, tahini, nut butters
- Proteins: tofu, tempeh, seitan, higher-protein meat alternatives (watch salt) and unsweetened soy yoghurts, small portions of pulses
As pulses and wholegrains contain carbs, strict plant-based keto diets often rely more on tofu/tempeh/seitan, nuts/seeds, and non-starchy veg, with very limited legumes and grains. More flexible plant-based low-carb patterns can include modest amounts of beans, lentils, and wholegrains.
If you would like to work with a kidney dietitian privately who can support you with a kidney-friendly diet, why not book a FREE 15-minute enquiry call to find out how 1:1 support could help you.
Why are keto diets popular?
There are a few big reasons keto has taken off:
1. Weight loss (especially early on): Cutting carbs lowers insulin, and our body uses up glycogen (the stored form of sugar in our body). As glycogen is stored in the body attached to water, when glycogen is used up, you also get rid of water, so people often see the scales drop quickly because of water loss. This early “win” can feel motivating, and some continue to lose weight if their overall calorie intake then goes down.
2. Type 2 diabetes & blood sugar control: Lower carbohydrate intake can reduce sugar spikes after meals, reduce average blood sugar readings, and improve insulin sensitivity for some people. Those benefits can feel dramatic, leading to claims of diabetes reversal.
3. Clear rules = easier decisions: Keto’s rigid “can/can’t eat” list reduces choice overload. For some personalities, tight guardrails make shopping, cooking, and eating out simpler (even if it’s more restrictive).
4. Appetite suppression & fewer cravings: Many find higher-fat, moderate-protein meals more satisfying. Stable blood sugars and feeling less hungry can mean fewer between-meal snacks.
5. Visible non-scale wins: Some people report better energy, reduced “brain fog,” and improved focus once they’re in ketosis – another reason the approach feels rewarding.
Are keto diets safe for kidney disease?
The short answer is we don’t really know – the evidence of following a keto diet with CKD is limited, but there are certainly a few concerns to consider.
A few small, short-term studies suggest keto or very-low-carb approaches can improve weight, blood pressure and diabetes control in some people with CKD, which sounds like good news. However, these studies are small, adherence to these diets is often poor, medical supervision is usually recommended, and long-term kidney and heart outcomes are simply unknown.
Here are some of the concerns we have (as do many kidney healthcare professionals):
- Too much protein: Higher protein intake may accelerate kidney decline, and most keto diets, especially those that are animal-based have a higher protein load.
- High acid load & acidosis risk: Animal-based, low-fruit/veg diets raise the amount of acid from the diet and high acid load is linked with faster progression of kidney disease. It is also linked to metabolic acidosis – a CKD complication causing the blood to be more acidic which can also lead to loss of muscle, and also higher potassium levels and bone problems.
- Cardiovascular risk: LDL-cholesterol (bad cholesterol) can increase on keto diets, which is a risk factor for cardiovascular disease. Swapping saturated fats with healthier fats such as olive oil, rapeseed oil, nuts, seeds and avocado may help with this. Though you may need to moderate intake of some of these foods if you are on a low-potassium diet.
- Kidney stones: Keto diets are associated with a higher risk of developing kidney stones.
- Side effects/tolerability: Early “keto flu” (fatigue, nausea, dizziness), constipation, dehydration and cramps are common reasons people stop a keto diet – and this explains why people struggle to comply with these diets.
- Disordered eating: Very rigid “can/can’t” lists and labelling of foods as good or bad can lead to an unhealthy relationship with food, which can be harmful to overall health.
- Inadequate nutrition: Cutting out food such as wholegrains, fruits and vegetables, and pulses can lead to constipation and micronutrient deficiencies.
The bottom line is that keto or very-low-carb diets are not generally recommended for people with CKD as the evidence is still lacking on their longer-term safety and the impact on kidney health, and therefore do NOT recommend keto diets, especially animal-heavy and unsupervised by a healthcare professional.
For most people with Stage 3–4 CKD, less restrictive, kidney-friendly alternative diets are favoured – we’ll be sharing what some of those are later in the post.
However, there are emerging reviews that argue a possible role for keto diets in polycystic kidney disease (PCKD).
Keto diets and polycystic kidney disease (PCKD)
A PCKD-adapted keto approach is typically low-carb, moderate-protein (not high), and high-fat, with an emphasis on plant fats and plant proteins.
The research so far is considered to be more experimental, with some early results. Some of the potential benefits are:
- Reduced body weight
- Potential slowing cyst growth (although this was not proven after 3 months on the diet and no longer-term robust studies have been carried out yet)
- Possible improvement in estimated kidney function (it is as yet impossible to know if this was due to an actual improvement in kidney function or just a change in diet)
- Reduced liver volume
However, while initial findings may look promising, keto diets are still not routinely recommended as the evidence simply isn’t there yet. Not only that, the diet is challenging to undertake with some significant risks to health.The diet requires careful attention to address optimum protein source and quantity, optimum calorie intake mostly from fat, cholesterol management, stone prevention, and minimising diet acid load. More research is certainly needed to confirm long-term safety and efficacy before keto diets are routinely recommended for PCKD.
Alternative approaches to keto diets for CKD
There’s no one-size-fits-all plan – especially with CKD. The “best” approach is the one that meets your health goals, protects kidney function, supports heart health, and feels realistic for you in the long term.
Here are some options to consider:
1. Lower-carb/modified keto
A gentler version of keto that reduces carbs but doesn’t aim for ketosis – a more flexible carbohydrate intake, moderate protein, and healthy plant fats from olive/rapeseed oil, nuts, seeds, avocado. Includes plenty of non-starchy veg and smaller portions of wholegrains and fruit.
2. Mediterranean-style diet
A plant-based diet rich in veg, fruit, legumes, wholegrains, nuts, seeds, olive oil, plus fish and modest dairy. This type of diet contains minimal processed foods and red meats/chicken.
3. DASH diet (Dietary Approaches to Stop Hypertension)
A diet designed to lower blood pressure: high in veg, fruit, wholegrains, low-fat dairy, lean proteins, nuts/legumes, and low in salt.
4. Lower protein diet
A lower protein diet may have a positive impact on the progression of CKD, while ensuring adequate calories from carbohydrates and fats, ideally supervised to minimise any risk of weight loss and malnutrition.
5. Time-restricted eating
Time-restricted eating (sometimes referred to as intermittent fasting) refers to a restricted daily eating window, such as the 16:8 (an 8hr eating window, generally during the day e.g. from 11am to 7pm). This is a gentler way of promoting ketosis compared to a ketogenic diet, although the impact on kidney health specifically remains unknown.
The benefits of the above approaches include one or more of the following:
- Good for heart health
- Moderate protein, which is beneficial for CKD
- Generally easier to continue long term and to eat out/socialise with
- More flexible and sustainable; fewer side effects eg keto flu, constipation
- Allows more fibre (better gut health, bowel regularity) and a wider food variety, which is helpful for micronutrients
- May be useful for improved diabetes control
Key takeaways
✅ Keto diets typically have 5–10% of calories from carbs (often 20–50 g/day), high fat, moderate/high protein. Low-carb is broader and more flexible.
✅ People like keto because of weight loss, steadier blood sugar levels, clear rules and reduced appetite – but these benefits can often be achieved with less restrictive approaches.
✅ Keto diets are not recommended for CKD due to increased protein intake, higher acid load, increased cholesterol, kidney stone risk and lack of long-term data on kidney and heart outcomes.
✅ Small, short experimental studies suggest possible benefits from plant-based, moderate-protein keto diets, but medical supervision is essential and long-term safety is unknown, so it is still not recommended.
✅ Better dietary approaches for CKD include lower-carb/modified keto, Mediterranean diet, DASH diet and low protein diets.
✅ Personalisation is key: your best plan depends on CKD stage, blood results and health goals.
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Disclaimer: This advice is primarily for individuals with CKD Stages 3 & 4. It is solely educational and provides general advice only. It is not a substitute for seeing a registered dietitian or another qualified healthcare professional.
