An overview and potential benefits and risks

What do gluten-free, ketogenic and zone all have in common? They’re all trendy diets. In 2018, my patients inquired the most about the potential health benefits and risks of ketogenic diets.


Ketogenic diets eliminate carbohydrate-rich foods, such as bread, pasta and most fruits. An example of a ketogenic diet: fat at every meal (such as eggs, meat or fish); unsaturated fats (such as olive oil and avocado oil); saturated fats (such as butter and red meat); low carbohydrate vegetables (such as cauliflower, broccoli and asparagus) and low carbohydrate fruits (such as berries) in small portions. Thus, these diets provide between 5% to 10% of daily calories from carbohydrates, 10% to 20% of protein and 70% to 80% from fat. The Dietary Guidelines for Americans recommends 10% to 30% of calories from protein, 45% to 65% percent of calories from carbohydrates and 25% to 35% from fat.

Because these diets deprive the body of glucose, which comes from carbohydrates and proteins and creates energy, the body initially obtains glucose from the liver. After a few days of carb restriction, however, the body uses ketones from fat for fuel, causing a state of ketosis and weight loss.

Image courtesy of sudowoodo/


Aside from weight loss, the decanoic acid in ketogenic diets decreases uncontrolled epilepsy in children. Additionally, emerging evidence reveals decreased seizure frequency in adults who have refractory epilepsy and cognitive improvements in Alzheimer’s disease patients.

Also, short-term studies (over 12 weeks) show reduced insulin resistance in Type 2 diabetes patients.


Carbohydrates are everywhere, making these diets difficult to maintain. Also, as both the liver and kidney help to metabolize protein, ketogenic diets may not be safe in those who have liver or kidney disease. In rare cases, excessive ketone blood levels can cause a dangerous level of acid in the blood called ketoacidosis, altering the normal functioning of internal organs, such as the kidneys.

Other risks include hunger, fatigue, low mood, brain fog, headaches, bad breath, diarrhea, leg muscle cramps, insomnia, temporary hair loss, rash, pancreatitis, selenium deficiency, decreased alcohol tolerance, kidney stones, increased blood levels of uric acid, which can lead to gout and osteoporosis, fiber deficiency, which can cause digestive tract and heart diseases, and constipation and optic neuropathy, thought due to a lack of thiamine (B vitamin). Other concerns: the long-term high in-take of saturated fats and cardiovascular issues and the risk of overproduction of ketones in Type 1 diabetes patients because they don’t have insulin to prevent it.


When patients divulge they have begun this diet or would like to start it, advise they seek a medical doctor and dietitian who can ensure their body maintains ketosis, while avoiding the dangerous state of ketoacidosis. OM