Protein on Keto: How Much You Need and Is Too Much Bad?

On this page

1. How much protein do you need on keto?
2. How much protein is too much?
3. Does protein affect ketosis?
4. Protein and carbs in everyday foods
5. Meat, fish, eggs, dairy and plants
6. Protein powders and protein products
7. Who should get advice first
8. FAQs
9. Sources

This guide is about protein in general on a keto diet: how much UK bodies recommend, what they say about too much, and how many carbs come with everyday protein foods. If you want detail on protein powder, see our guide to whether whey protein is keto, and for beef, lamb and pork, our guide to whether red meat is keto friendly.

How much protein do you need on keto?

A ketogenic diet is defined by how much carbohydrate you eat. The British Dietetic Association (BDA) puts a very low carb (ketogenic) diet at 20–50g of carbohydrate a day. We haven't found a UK protein recommendation written for keto diets, so the general guidance for adults is the one to start from.

The British Nutrition Foundation (BNF) says: "The Reference Nutrient Intake (RNI) is 0.75g of protein per kilogram body weight per day for adults, with additional requirements for growth and repair, including for children and in pregnancy." For someone who weighs 70kg, that works out at 52.5g of protein a day (our calculation).

The UK government's dietary recommendations, published by Public Health England in 2016, turn the RNI into daily amounts. They take the protein figures from the Department of Health's 1991 report on Dietary Reference Values.

Government Dietary Recommendations, Public Health England (2016), Table 2. The BNF's table of the same 1991 figures groups the ages as 19–50 and 50+.

The BNF notes that these amounts were "based on average body weights at the time the recommendations were made" and adds: "(note that this was in 1991 and that average body weights now are likely to be higher)". Its table from the same 1991 figures adds 6g a day in pregnancy, and 11g a day while breastfeeding a baby aged 0–6 months (8g once the baby is 6 months or older).

Some groups may need more. The BDA's sport and exercise fact sheet says athletes in strength and endurance sports have a higher requirement, of about 1.4–2.0g per kg a day, than people who don't exercise (0.75g per kg a day). It also says that "in most cases, providing energy requirements are met, a healthy, balanced diet should provide enough protein to meet any increased requirements." For older adults, the British Heart Foundation (BHF) says: "To prevent age-related muscle loss (sarcopenia), people over 65 are advised to eat about 1g to 1.2g of protein per kg of body weight per day".

How much protein is too much?

There's no official upper limit, the BHF says. The BNF says: "When the RNIs were set there were some concerns about risks from high protein diets but in the absence of enough data to establish an upper limit, the Department of Health advised adults should avoid protein intakes which are more than twice the RNI." For a 70kg adult, twice the RNI is 105g of protein a day (our calculation).

The BNF adds that in 2012 the European Food Safety Authority (EFSA) "also stated that data was still insufficient to establish a Tolerable Upper Intake Level (UL) for protein and that the potential detrimental effects of very high protein intake remain controversial."

The BHF gives a different figure. It says: "However, while there is no official upper limit on the amount of protein to eat, regularly eating more than 2g per kg per day (which is 1.25g per kg more than recommended) can put a strain on the kidneys, especially in those with kidney issues." So the Department of Health's advice works out at 1.5g per kg a day (our calculation), and the BHF's figure is 2g per kg a day.

On what happens to protein you don't need, the BHF says: "For most people, eating a little more protein is not harmful but any extra the body does not need will either be burned for energy or stored as fat." The BNF says: "Any excess protein consumed is used in the body to provide energy. One gram of protein provides 17kJ (4kcal)."

Does protein affect ketosis?

You'll often read that too much protein will kick you out of ketosis. We haven't found NHS, BDA or BNF guidance that sets a protein limit for staying in ketosis on an everyday keto diet. The BDA's low carb diets fact sheet defines each type of low carb diet by grams of carbohydrate a day, not by protein.

The UK guidance we found that does describe protein in ketogenic diets is about medical ketogenic diets used to treat epilepsy. The Epilepsy Society says: "Ketogenic diets are a very high fat, very low carbohydrate, moderate protein diet that have been used since the 1920s to treat epilepsy." It says the classical ketogenic diet "includes very little carbohydrate and protein. Each meal includes a strictly measured ratio of fat to carbohydrate and protein." The modified Atkins diet and modified ketogenic diet "are often considered more flexible than the classical ketogenic diets, as more protein can be eaten, and approximate portion sizes may be used in place of weighed recipes."

These are medical treatments, not everyday diets. The Epilepsy Society says: "Dietary treatments for epilepsy must only be followed with the support of an experienced epilepsy specialist and dietitian (food specialist)."

Protein and carbs in everyday foods

CoFID 2021, the UK's official food composition data, gives these figures per 100g. In this table, the meat, fish, egg and cheese rows list 0.1g of carbohydrate or less, and the almond and lentil rows list 5.3g and 16.9g.

CoFID 2021, sheet 1.3 Proximates, food codes 18-323, 16-359, 16-416, 18-507, 12-346, 12-940, 12-555, 13-570, 14-896 and 13-658. Figures change with the cut and cooking method, so check the row for the food you eat.

For portion sizes, the BDA's sport and exercise fact sheet lists foods that each contain about 20g of protein. They include 2 medium slices (75g cooked weight) of beef, lamb or pork, 1 small chicken breast (75g cooked weight), 1 medium fillet or steak of grilled fish (100g), 1 small can of tuna or salmon (100g), 3 medium eggs, and half a 450g pot of Greek yoghurt (225g).

At 4.8g of carbohydrate per 100g in CoFID, that 225g of Greek style yoghurt has about 10.8g of carbs (our calculation). That's about a fifth to a half of a 20–50g day (our calculation), so it's worth counting dairy and plant proteins as well as meat. Our guides to whether eggs are keto and whether cheese is keto have more figures.

Meat, fish, eggs, dairy and plants

The BDA's low carb diets fact sheet says: "Base your diet on fresh, unprocessed foods where possible and include plenty of low carb vegetables (such as green veg, mushrooms, courgettes) and salad, some fruit, some dairy foods and lean meat, poultry, fish and eggs."

Meat. The NHS page Meat in your diet says: "If you currently eat more than 90g (cooked weight) of red or processed meat a day, it is recommended that you cut down to 70g." It lists red meat as beef, lamb, mutton, pork, veal, venison and goat. The Eatwell Guide says: "Choose lean cuts of meat and mince, and eat less red and processed meat like bacon, ham and sausages."

Fish. The NHS page on fish and shellfish says: "A healthy, balanced diet should include at least 2 portions of fish a week, including 1 of oily fish." It adds: "The advice may be different if you're pregnant, breastfeeding or a child."

Plants. The BNF says: "Pulses such as kidney beans, baked beans, chickpeas and lentils all provide a plant-based source of protein." On a low carb diet, the BDA says: "Depending on the extent of carb restriction, some people also include pulses such as dried peas and beans." The lentil row in the table above lists 16.9g of carbohydrate per 100g of boiled red lentils.

Protein powders and protein products

The BNF says: "As most of us are eating more than enough protein already, we do not need to add protein supplements or special products with added protein into our diets." The BDA says supplements "will not compensate for poor food choices but may be helpful in certain situations", and that if you're considering one, you should consult a registered practitioner. Our whey protein guide covers the carbs in protein powders.

If you'd rather get protein from food, our German-Style High Protein Bread lists 10.6g of protein and 6.3g of carbohydrate per 50g slice (21.1g and 12.6g per 100g). It's made with wholemeal wheat flour and wheat protein, so it contains gluten. Check the pack for full ingredients and allergen information. Each 40g bar in our Keto Bar Variety Box lists 6g of carbohydrate, of which 3.3g is polyols, so 2.7g of net carbs, and 5.2g (Salted Caramel) or 5.3g (Cocoa Orange) of protein; both flavours contain nuts. Free delivery on orders over £30.

Who should get advice first

Some people should talk to a health professional before changing how much protein they eat or starting keto.

• Kidney disease. Kidney Care UK says: "Sometimes, changes to your diet are needed if your kidney disease progresses and your kidney function declines. Your healthcare team will check your kidney function, nutritional status and overall health to see if and when you need to make any special changes to your diet." It also says: "Please speak to your kidney dietitian for individual dietary advice, and for information about your specific dietary requirements." The BHF's warning about more than 2g per kg a day mentions people with kidney issues in particular.
• Pregnancy. The BDA says: "Ketogenic diets should not be followed by women who are pregnant." If you're pregnant, the NHS page Meat in your diet says to avoid raw and undercooked meat, pâté of all types (including vegetable pâté), liver and liver products, and game meats such as goose, partridge or pheasant.
• Medication and medical conditions. The BDA says: "If you have type 2 diabetes, you may need to reduce some medication such as insulin or sulfonylureas to avoid hypoglycaemia, and this should be done under medical supervision." It also says that "if you have a medical condition you are advised to seek advice from a dietitian."

Frequently asked questions

Sources

• Public Health England. Government Dietary Recommendations (2016), Table 2 (protein in grams a day for adults, from the 1991 Dietary Reference Values).
• British Nutrition Foundation. Nutrition information about protein and plant-based protein (the RNI of 0.75g per kg, extra protein in pregnancy and breastfeeding, the Department of Health's twice-the-RNI advice, EFSA on an upper limit, excess protein, pulses, supplements). Checked 3 November 2026.
• British Dietetic Association. Low carb diets food fact sheet (October 2019; 20–50g of carbohydrate a day on a very low carb, ketogenic diet; foods to base the diet on; pulses; pregnancy; medication and medical conditions) and Sport and exercise food fact sheet (May 2026; protein needs, 20g protein portions, supplements).
• British Heart Foundation. Protein: how much do you need? (more than 2g per kg a day and the kidneys, extra protein, people over 65). Checked 3 November 2026.
• NHS. Meat in your diet (red and processed meat, eating meat when you're pregnant), The Eatwell Guide (lean cuts, red and processed meat) and Fish and shellfish (portions of fish a week). Checked 3 November 2026.
• Epilepsy Society. Ketogenic diets (protein in medical ketogenic diets, specialist supervision). Checked 3 November 2026.
• Kidney Care UK. Healthy eating and lifestyle for your kidneys (diet changes as kidney disease progresses, kidney dietitians). Checked 3 November 2026.
• Public Health England / Food Standards Agency. Composition of Foods Integrated Dataset (CoFID) 2021: sheet 1.3 Proximates, food codes as listed under the table.
• Groovy Keto product pages: German-Style High Protein Bread and Keto Bar Variety Box (ingredients, allergens, nutrition per serving). Checked 3 November 2026.