A keto diet is an eating plan focusing on foods that have plenty of healthy fats, sufficient protein and very few carbohydrates. The goal is to gain more calories from the fat than from the carbohydrates.
The diet works by depleting the body of its stores of sugar. As a consequence, fat for energy will start to break down. This results in the development of ketones called molecules which the body uses for fuel. It can also lead to weight loss as the body burns fats.
Many types of keto diet are available, including Standard Ketogenic Diet and Cyclical Ketogenic Diet.
We describe the advantages of the keto diet, as well as its dangers in this article.
Supports weight loss
The ketogenic diet can help to promote weight loss in many ways, including metabolism enhancement and appetite reduction.
Ketogenic diets are foods that fill a person up and that can reduce the hormones that cause hunger. For these reasons, a keto diet can lower the appetite and encourage weight loss.
Researchers found in a 2013 meta-analysis of 13 different randomized controlled trials that people following ketogenic diets lost 2 pounds (lbs) more than those following low-fat diets over 1 year.
Similarly, another review of 11 studies found that, after 6 months, people on a ketogenic diet lost 5 lbs more than those on low-fat diets.
Acne has many common causes and may have ties to diet and blood sugar in certain cases.
Eating a diet high in processed and refined carbohydrates can alter the balance of gut bacteria and cause blood sugar to rise and fall dramatically, both of which can adversely affect skin health.
According to a 2012 report, a ketogenic diet could reduce some people’s acne symptoms by reducing carb intake
Find out more about acne here.
May reduce risk of certain cancers
Researchers also explored the ketogenic diet’s role in helping avoid or even cure other cancers.
One research showed that the ketogenic diet could be a safe and effective alternative treatment for use in people with some cancers, alongside chemotherapy and radiation therapy. This is because, in cancer cells, it can cause more oxidative stress than normal cells, causing them to die.
Another recent 2018 study indicates that because the ketogenic diet lowers blood sugar, the risk of insulin complications may also be reduced. Insulin is a blood sugar regulation factor that may have links to certain cancers.
Although some study indicates the ketogenic diet may have some value in treating cancer, studies in this area are minimal. To better appreciate the possible benefits of the ketogenic diet in cancer prevention and care, researchers need to perform further studies.
May improve heart health
It is important that when a person follows the ketogenic diet they choose healthy foods. Eating healthier fats, such as avocados rather than less healthy fats, such as pork rinds, can help boost heart health by reducing cholesterol, some evidence suggests.
A 2017 analysis of animal and human research on a keto diet found that certain individuals reported a substantial decrease in total cholesterol levels, low-density lipoprotein (LDL), or poor cholesterol, and triglycerides, as well as an rise in high-density lipoprotein (HDL), or “healthy” cholesterol.
High cholesterol levels can increase the risk of developing cardiovascular disease. Consequently, reducing the impact of a keto diet on cholesterol will reduce the risk of heart complications in a person.
The review concluded, however, that the positive effects of a diet on heart health depend on the quality of the diet. Hence consuming healthy, nutritionally balanced food is essential when following the keto diet.
May protect brain function
Some research, such as this review in 2019, indicate the ketones produced during the keto diet have neuroprotective benefits, which means they can reinforce and protect the brain and nerve cells.
That is why a keto diet can help a person avoid or control conditions like Alzheimer’s disease.
Further work is, however, required into the effects of a keto diet on the brain.
Read more about Alzheimer’s disease.
Potentially reduces seizures
Within a keto diet the combination of fat, protein, and carbs affects the way the body uses energy, resulting within ketosis. Ketosis is a biochemical cycle that the body uses ketone bodies for fuel during.
The Epilepsy Foundation suggests that ketosis in people with epilepsy can reduce seizures — especially those who have not responded to other methods of treatment. More research is needed on how successful this is as it tends to have the greatest impact on children with focal seizures.
A analysis for 2019 supports the theory that a keto diet will benefit people with epilepsy. The ketogenic diet can the symptoms of epilepsy by several different mechanisms.
Improves PCOS symptoms
Polycystic ovary syndrome (PCOS) is a hormonal condition that can lead to excess male hormones, ovulatory dysfunction and ovaries. A high carbohydrate diet can cause adverse effects, such as skin problems and weight gain, in people with PCOS.
Clinical research on ketogenic diet and PCOS are not numerous. One 2005 pilot study investigated five women over 24 weeks. The researchers find multiple PCOS markers improved with a ketogenic diet including:
- weight loss
- hormone balance
- ratios of luteinizing hormone (LH) and follicle-stimulating hormone (FSH)
- levels of fasting insulin
Another 2019 research analysis showed a keto diet has beneficial benefits for people with hormonal disorders including PCOS and type 2 diabetes. Researchers also made aware, however, that the findings were too complex to recommend a keto diet as a general PCOS treatment.
Risks and complications
The ketogenic diet can offer a number of health benefits. However, remaining on a long-term ketogenic diet may have an adverse health effect including an increased risk of the following health problems:
- kidney stones
- excess protein in the blood
- mineral and vitamin deficiencies
- a build up of fat in the liver
The keto diet can cause adverse side effects known to many as keto flu. Those negative effects can include:
- low blood sugar
- a low tolerance for exercise
These symptoms are especially common at the start of the diet, as the body adjusts to its new source of energy.
Some populations should avoid the keto diet, including:
- people with diabetes who are insulin-dependent
- people who have eating disorders
- those with kidney disease or pancreatitis
- women during pregnancy and breastfeeding
Those who take a type of medication called cotransporter 2 sodium-glucose (SGLT2) inhibitors for form 2 diabetes do not adopt a keto diet either. This medication increases the risk of diabetic ketoacidosis, which is a dangerous condition which increases blood acidity.
It is important to talk to a doctor, dietitian, or trusted healthcare provider about any intended diet plan, especially for people who are trying to manage a health problem or disease.
People who are looking to start the keto diet should seek a doctor’s consultation and check if they have diabetes, hypoglycemia, heart disease, or any other health conditions to ensure a safe eating pattern for the keto diet.
Bear in mind that there is a lack of research on the long term effects of ketogenic diet. It is uncertain if it is more important to sustain the diet for longer periods than less restrictive healthy eating habits.
A ketogenic diet restricts carbohydrates, or significantly limits them. Some carbohydrates do provide health benefits, however. People should eat a diet that contains a range of nutrient-dense, fibrous carbohydrates, such as fruits and vegetables, alongside balanced protein sources, and healthy fats for a less restrictive dietary approach.
How long can I maintain a keto diet safely?
There is a significant amount of research supporting the possible benefits of ketogenic diet, including control of weight loss and blood sugar. However, most research only took place during brief periods of a couple of weeks or months.
Some studies show the advantages of following the ketogenic diet for longer periods of up to 2 years. There is also a shortage of research exploring the possible side effects of adopting a ketogenic diet for prolonged periods of time.
One recent cohort study that tracked 432,179 adults over 25 years correlated large and low intakes of carbohydrates with a higher mortality risk than moderate intakes of carbohydrates. In particular, people who consumed more than 70 per cent or less than 40 per cent of carbohydrate calories were at a higher mortality risk.
While it is likely that if you follow the ketogenic diet correctly on a short-term basis you will lose weight, research suggests that it is probably not the healthiest diet to follow in the long run.
If you want to follow the ketogenic diet, it would be better to limit this dietary trend to a few months, then the transition back to a less restrictive diet that you can maintain for a long time. No matter what diet you are pursuing, remember to make sure you eat whole healthy foods. Jillian Kubala, MS, RD
Answers represent our medical experts’ opinions. All material is purely informational and medical advice should not be considered.