Keto diet vs low carb: what's the difference?

keto diet vs low carb
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Keto diet vs low carb: what’s the difference and which is better? Although the two diets both involve cutting carbs and can help with weight loss, the keto diet (short for ketogenic) is a far more restrictive way of eating and involves limiting carb intake and eating a high amount of fat, with moderate protein.

“Keto means the body has switched into ketosis and is using fat instead of glucose for fuel,” says diet expert Heidi Normanton, founder of Heylo. “Meanwhile low carb diets limit the amount of carbohydrates consumed, especially simple and refined ones found in sugary foods, pasta and bread. Going low carb helps regulate blood sugar but it doesn’t produce ketosis, so the body will first use the glucose stored as energy, then move onto fat for fuel.”

It’s important to have an understanding of your body and the calories and nutrients required for it to function effectively before starting a new diet, adds elite coach Farren Morgan, who runs The Tactical Athlete. He advises speaking to a dietician or a health professional first.

In this article we look at the key differences between the keto diet vs low carb, so you can decide if either plan is right for you.

What is a keto diet?

“A keto diet, also known as a ketogenic diet, is based on lowering your carbohydrate intake and increasing your intake of healthy fats,” says Morgan. 

It’s fairly restrictive, but while all keto diets are low carb, not all low carb diets are keto. The keto diet involves getting 70% of daily calories from fat, 20% from protein and 10% from carbohydrates.

Keto diet - eggs and bacon on a frying pan

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What is the low carb diet?

Like keto, low carb diets follow the same principle of cutting carbs and replacing them with protein, healthy fats and vegetables. “Carbohydrates are easier to digest, but don’t provide the same essential nutrients that proteins and fats do for the growth and development of your physique,” explains Morgan.

woman following a low carb meal plan

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Keto diet vs low carb: similarities

“Both diets have the same objective in mind – weight loss - but keto diets fall as a subcategory of a low carb diet, while low carb diets represent the umbrella that covers a large variety of other diets that it has under its belt,” says Morgan.

Put simply, a low carb diet is very relative, and doesn’t have specific amounts of carbs you should or shouldn’t consume – unless you are following a set diet plan like Atkins or Dukan. Going low carb also means you’re probably not eating as much fat as you would if you were trying to force the body into ketosis, and you’ll be eating lots of filling lean proteins and vegetables to stay energized.

Both plans have some noticeable health benefits, too. A study in the BMJ revealed that going low carb was associated with higher states of remission among people with type 2 diabetes, while keto diets could improve heart health, according to another study in the Journal of the American College of Cardiology. Further research published in the Frontiers in Neuroscience journal found that the keto diet helps prevent seizures and treat epilepsy, something it was first used for in the 1920s. 

Keto diet vs low carb: differences

First up, your carbohydrate intake will differ depending on whether you’re following a keto diet or simply low carb. “With a low carb diet you'd be expected to eat 50-150 grams of carbs per day, but keto diets are restricted to just 50 grams,” says Morgan.

Protein intake is another factor that differs. “Low carb diets generally require a large intake of protein, but keto diets moderate your protein consumption to between 20-22% of your total calories. Keto diets also require a large intake of fats compared with low carb diets to compensate for the protein and carbohydrates.”

person meal prepping on a low carb diet

(Image credit: Getty Images)

Normanton says if your goal is to build muscle, then going low carb could be a better option, as glucose is needed to repair muscle. “Many people also feel that a low carb diet is an easier transition and therefore some start with that, then move onto keto,” she says. “The keto diet is also very popular with athletes and some marathon runners swear by it as their bodies are ‘fat adapted’ and it can help them maintain endurance for longer periods of time without needing carbs to refuel.” 

But there are some slightly unpleasant side effects associated with both plans. “Transitioning into these diets will be a process, especially regarding the keto diet,” says Morgan. “With low carb diets you may feel weak or experience constipation due to the impact of your micronutrient consumption. If you’re new to the ketogenic diet, you may experience the ‘keto flu’, which includes symptoms such as headaches, brain fog, irritability, fatigue, and lack of motivation.”

Morgan says that these symptoms generally last for a week or less, but in extreme scenarios they have been known to last to a month, so it's important to be mentally prepared and fully equipped with an experienced professional to guide you before you decide to start your diet.

Keto diet vs low carb: Which diet is best?

“Both are effective for weight loss, so what ultimately matters is which diet is best for you and your body,” says Morgan. “If you're looking to acquire a physique that's lean yet muscular you may go for the low carb diet, while those looking for an overall slim physique may lean towards keto.”


D’Andrea Meira, I., Romão, T. T., Pires Do Prado, H. J., Krüger, L. T., Pires, M. E. P., & da Conceição, P. O. (2019). Ketogenic Diet and Epilepsy: What We Know So Far. Frontiers in Neuroscience, 13.

Goldenberg, J. Z., Day, A., Brinkworth, G. D., Sato, J., Yamada, S., Jönsson, T., Beardsley, J., Johnson, J. A., Thabane, L., & Johnston, B. C. (2021). Efficacy and safety of low and very low carbohydrate diets for type 2 diabetes remission: systematic review and meta-analysis of published and unpublished randomized trial data. BMJ, m4743.

Yurista, S. R., Chong, C. R., Badimon, J. J., Kelly, D. P., de Boer, R. A., & Westenbrink, B. D. (2021). Therapeutic Potential of Ketone Bodies for Patients With Cardiovascular Disease. Journal of the American College of Cardiology, 77(13), 1660–1669.

Maddy Biddulph

Maddy has been a writer and editor for 25 years, and has worked for some of the UK's bestselling newspapers and women’s magazines, including Marie Claire, The Sunday Times and Women's Health. Maddy is also a fully qualified Level 3 Personal Trainer, specializing in helping busy women over 40 navigate menopause.