Keto Diet While Breastfeeding: Safety And Effectiveness

  • Maha AhmedMBBS, Intarnal Medicine and General Surgery, Cairo University, Egypt


Pregnancy and breastfeeding can cause physical changes to your body, especially weight gain. You might have heard of the keto diet and its effects on weight loss, and are wondering about the safety and effects of the keto diet while breastfeeding.

A keto diet (ketogenic diet) is a diet that is very low in carbohydrates, moderate in protein, and high in fat.

The keto diet is effective in weight loss and packs several health benefits. It also has its risks and side effects. Doctors recommend a healthy balanced diet for breastfeeding mothers because there is limited research and understanding of how the keto diet affects breastfeeding.

The keto diet: understanding the basics

What is a keto diet?

A keto diet (ketogenic diet) is a diet that is very low in carbohydrates, moderate in protein, and high in fat.1 The classic ketogenic diet is defined as a diet with one gram of protein per kilogram of body weight, 10-15g carbohydrates per day, and the remaining calories from fat.2

How the keto diet works

Usually, carbohydrates should make up about 45-65% of our calorie intake.3 This is 225g-325g of carbohydrates daily. Still, it reduces to as low as 10g per day in a keto diet.

Your body gets its energy from glucose, which is the breakdown of carbohydrates. When you consume a diet low in carbohydrates, there is no sufficient glucose for the body to use as energy. As a result, your body breaks down fat. It is this breakdown of fat that produces what is known as ketones. These ketones serve as fuel for the body in replacement of glucose. The process of producing ketones is known as ketogenesis.4

Ketogenesis can also occur during starvation or fasting and low insulin production or insulin resistance. This is why ketones can be found in the blood of starving people or fasting and in diabetics.5

Benefits and potential risks of the keto diet

The earliest use of the keto diet was in 1921 to treat childhood epilepsy.2 Since then, the keto diet has been explored and studied for better understanding.

The keto diet is beneficial for several reasons. It treats epilepsy, improves type 2 diabetes, reduces blood sugar, and causes weight loss for obese individuals.1

When there is low glucose in the blood, the body produces ketones due to the breakdown of fat. This reduces the use of insulin that would normally break down glucose because the body uses ketones as the primary energy source. As a result, there is improvement in the type 2 diabetic patient and reduces high insulin levels in the blood (hyperinsulinaemia).

The keto diet has also been used to treat obesity and is known to improve Polycystic Ovarian Syndrome (PCOS)—a condition that affects the ovaries.6

Although beneficial, the keto diet has the potential risks of kidney stones1, increased cardiovascular risks due to dyslipidaemia (abnormally raised cholesterol or fats in the blood)6,7, dehydration1, and ketoacidosis (a metabolic state associated with high blood and urine concentrations of ketone bodies), especially in diabetics.2,6

Breastfeeding and nutritional requirements

Breastfeeding is necessary for the proper growth and development of the newborn. Breast milk supplies all the nutrients the baby needs, and benefits are associated with exclusively breastfeeding a baby for the first six months of life. These include lower mortality rates, improvement in the most prevalent pathologies in the first months of life (otitis media, asthma), reduction in dental malocclusion (misaligned teeth), lower risk of obesity, and higher intelligence ratios.8

Breastfeeding moms need an additional 330 calories to 400 calories per day to cater to their calorie needs and the baby. When the mother takes in insufficient calories, it can affect breast milk production. This is because the body is looking for ways to maintain sufficiency and conserve energy, so it cuts off anything that isn’t necessary to the body’s needs.9

A lactating mother needs to eat a healthy balanced diet. It will supply your baby with the nutrients they need for healthy growth and development. Breastfeeding moms are also advised to eat protein-rich foods, whole grains, fruits and vegetables.

Safety and effectiveness of the keto diet while breastfeeding

The keto diet is effective for weight loss. It reduces blood sugar and improves diabetes.1 People have reported tremendous results in weight loss and a healthy blood sugar level.

Impact of the keto diet on milk supply

There is limited research on the effects of the keto diet on breast milk supply. Although diet restrictions could cause a low milk supply, there is no known association between energy supplementation as in the keto diet and breast milk supply.9

When you restrict your diet, you reduce the number of daily calories required for breastfeeding (330-400 calories more than average ), which could affect your milk supply. This is because your body conserves energy by restricting certain physiological activities like breastfeeding. Keeping you alive is the body’s top priority. However, with energy supplementation as seen in the keto diet, you still have the required energy but the energy source is different (fat instead of carbohydrates).

You may think breastfeeding on a keto diet would reduce the quality of breast milk your baby gets, but a study shows the keto diet doesn’t affect the quality of breast milk, but rather increases the number of calories. This is because of the extra fat content in the milk from the keto diet.10

The keto diet can also reduce appetite and cause the mother to feel full,11 which reduces the daily number of calories the mother needs to take. Health professionals advise breastfeeding mothers to take the daily caloric amount to meet the baby’s nutritional needs. Additionally, a study in Indonesia revealed that adequate maternal calorie intake is associated with fulfilling the recommended six months of exclusive breastfeeding.12

There is limited scientific research on the impact of the keto diet on breastfeeding, but from present studies, the keto diet seems to have little effect on breast milk supply.

Impact of the keto diet on breastfeeding mothers

Breastfeeding mothers consider the keto diet because of its effect on weight loss. Aside from weight loss, some studies indicate that the keto diet increases energy levels, reduces cravings for starchy foods, and improves well-being.13,14

Other side effects of the keto diet are dehydration, insomnia, constipation, diarrhoea, keto rash (rashes that suddenly appear on the body due to the keto diet) and keto flu.15 However, these side effects come when you initially start the keto diet, and they leave after a few weeks.

A major concern of starting a keto diet is the risk of ketoacidosis (buildup of ketones in the blood that it becomes acidic). Ketoacidosis while breastfeeding is rare but possible. There have been cases of breastfeeding moms rushed to the ER because of ketoacidosis.16

Ketoacidosis is a metabolic state associated with high blood and urine concentrations of ketone bodies. Ketoacidosis is mostly associated with diabetes, although it can be caused by starvation, drinking alcohol, and some medications. Symptoms include excessive thirst and urination, vomiting, weakness, and mental changes.17

Although there are benefits to the keto diet, breastfeeding mothers should consider the side effects and risks.

Consulting a healthcare professional

The keto diet is effective in weight loss, but there is limited research on its safety for breastfeeding mothers and how it affects breastfeeding. There is a need for more research to shed more light on the effects of the keto diet during breastfeeding.

Breastfeeding mothers should focus on eating a healthy balanced diet that helps to breastfeed rather than on special diets. There isn’t much understanding of how the keto diet could affect breastfeeding.

If you are a breastfeeding mother considering the keto diet, it is important to consult your doctor or a licensed lactation consultant. They will further advise you on the safest way to go about it and can monitor you in case of any adverse effects.


The keto diet is no doubt an effective diet for weight loss. Aside from weight loss, it has tremendous health benefits such as improved blood sugar, reduced insulin in the blood, improved PCOS, high energy levels and improved well-being.

As beneficial as the keto diet is, individuals have the risk of getting kidney stones, ketoacidosis, and cardiovascular diseases. There are also side effects to the keto diet like dehydration, insomnia, constipation, diarrhoea, keto rash and keto flu.

Not much is known about the safety and effects of breastfeeding. It is advised by health professionals for breastfeeding mothers to stick to a healthy balanced diet. However, if the keto diet is something you want to do, you should consult your doctor or lactation consultant. They will advise you on the best way to go about the diet and will also monitor you for any effects during your diet.


  1. Crosby L, Davis B, Joshi S, Jardine M, Paul J, Neola M, et al. Ketogenic diets and chronic disease: weighing the benefits against the risks. Frontiers in Nutrition [Internet]. 2021 [cited 2023 Jul 25];8. Available from:
  2. McGaugh E, Barthel B. A review of ketogenic diet and lifestyle. Mo Med [Internet]. 2022 [cited 2023 Jul 25];119(1):84–8. Available from:
  3. Slavin J, Carlson J. Carbohydrates1. Adv Nutr [Internet]. 2014 Nov 3 [cited 2023 Jul 25];5(6):760–1. Available from:
  4. Tanner HL, Dekker Nitert M, Callaway LK, Barrett HL. Ketones in pregnancy: why is it considered necessary to avoid them and what is the evidence behind their perceived risk? Diabetes Care [Internet]. 2021 Jan 1 [cited 2023 Jul 25];44(1):280–9. Available from:
  5. Vasim I, Majeed CN, DeBoer MD. Intermittent fasting and metabolic health. Nutrients [Internet]. 2022 Jan [cited 2023 Jul 25];14(3):631. Available from:
  6. Batch JT, Lamsal SP, Adkins M, Sultan S, Ramirez MN. Advantages and disadvantages of the ketogenic diet: a review article. Cureus [Internet]. 2020 Aug 10 [cited 2023 Jul 25]; Available from:
  7. Goldberg IJ, Ibrahim N, Bredefeld C, Foo S, Lim V, Gutman D, et al. Ketogenic diets, not for everyone. J Clin Lipidol [Internet]. 2021 [cited 2023 Jul 27];15(1):61–7. Available from:
  8. Sánchez C, Franco L, Regal P, Lamas A, Cepeda A, Fente C. Breast milk: a source of functional compounds with potential application in nutrition and therapy. Nutrients [Internet]. 2021 Mar [cited 2023 Jul 26];13(3):1026. Available from:
  9. Lactation I of M (US) C on NSDP and Milk volume [Internet]. National Academies Press (US); 1991 [cited 2023 Jul 27]. Available from: K235589/
  10. Mohammad MA, Sunehag AL, Haymond MW. Effect of dietary macronutrient composition under moderate hypocaloric intake on maternal adaptation during lactation234. The American Journal of Clinical Nutrition [Internet]. 2009 Jun 1 [cited 2023 Jul 27];89(6):1821–7. Available from:
  11. Gibson AA, Seimon RV, Lee CMY, Ayre J, Franklin J, Markovic TP, et al. Do ketogenic diets really suppress appetite? A systematic review and meta-analysis: Do ketogenic diets really suppress appetite? Obes Rev [Internet]. 2015 Jan [cited 2023 Jul 27];16(1):64–76. Available from:
  12. Fikawati S, Syafiq A, Mardatillah. Maternal calorie intake is a significant factor associated with 6 months of exclusive breastfeeding among lactating mothers in Depok City, Indonesia. Malaysian Journal of Nutrition [Internet]. 2017 [cited 2023 Jul 27];23(1):31–41. Available from:
  13. Cohen CW, Fontaine KR, Arend RC, Soleymani T, Gower BA. Favourable effects of a ketogenic diet on physical function, perceived energy, and food cravings in women with ovarian or endometrial cancer: a randomized, controlled trial. Nutrients [Internet]. 2018 Sep [cited 2023 Jul 27];10(9):1187. Available from:
  14. Zinn C, Wood M, Williden M, Chatterton S, Maunder E. Ketogenic diet benefits body composition and well-being but not performance in a pilot case study of New Zealand endurance athletes. Journal of the International Society of Sports Nutrition [Internet]. 2017 Jan 3 [cited 2023 Jul 27];14(1):22. Available from:
  15. Singh M. Ketogenic diet: a view on benefits and risks. 1 [Internet]. 2019 Nov 2 [cited 2023 Jul 28];22(8):132–6. Available from:
  16. Al Alawi AM, Al Flaiti A, Falhammar H. Lactation ketoacidosis: a systematic review of case reports. Medicina [Internet]. 2020 Jun [cited 2023 Jul 27];56(6):299. Available from:
  17. Ghimire P, Dhamoon AS. Ketoacidosis. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 [cited 2023 Jul 27]. Available from:
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

Get our health newsletter

Get daily health and wellness advice from our medical team.
Your privacy is important to us. Any information you provide to this website may be placed by us on our servers. If you do not agree do not provide the information.

Odinakachukwu Ndukwe

Bachelor's of Medical Laboratory Science, University of Cape Coast, Ghana

Odinakachukwu Ndukwe is a Medical Laboratory Scientist and a Marketing Communication Specialist that specializes in content strategy and brand storytelling. She has found a way to merge her passion for public health with communication for better healthcare delivery and experience. Her current focus is on public health and health communication.

Leave a Reply

Your email address will not be published. Required fields are marked * presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
Klarity is a citizen-centric health data management platform that enables citizens to securely access, control and share their own health data. Klarity Health Library aims to provide clear and evidence-based health and wellness related informative articles. 
Klarity / Managed Self Ltd
Alum House
5 Alum Chine Road
Westbourne Bournemouth BH4 8DT
VAT Number: 362 5758 74
Company Number: 10696687

Phone Number:

 +44 20 3239 9818