Keto

What is it?

Keto is a low carb diet. Unlike some of the other diets which focus on protein, a keto diet focuses on fat. In some cases, fat may contribute as high as 90% of calories consumed. Some unsaturated fats are encouraged such as almonds, walnuts, seeds, avocados, olive oil, and tofu. And saturated fats from oils like palm and coconut, as well as lard, butter, and cocoa butter are recommended in high amounts.

What does it do?

In a healthy diet, carbohydrates are the body’s main source of energy. When the body is deprived of carbs, it produces significantly less insulin and enters a catabolic state. This is when both fat and protein become the main sources of energy. As glycogen (carb) stores decrease, two pathways by which energy can be created kick into action. One is called gluconeogenesis and the other is ketogenesis.

In gluconeogenesis the body produces glucose in the liver from lactic acid, alanine, and glutamine. When glucose levels drop, gluconeogenesis can no longer keep up and ketogenesis kicks in.

Ketogenesis produces an alternate form of energy as ketone bodies. When the body can no longer use glucose, fats begin to breakdown producing ketone bodies. This is known as “nutritional ketosis” and will continue as long as the body is deprived of carbohydrates.

Ketone bodies are utilized for energy by the heart, muscles, and kidneys. They can also cross the blood-brain barrier to provide an alternative source of energy to the brain. Red blood cells and the liver cannot utilize ketone bodies for energy. Because ketone bodies are so energy efficient, the body can maintain efficient fuel production even in a caloric deficiency. This is the reason this diet is used by individuals to help with weight loss.

What does the research say?

In the short-term, a ketogenic diet has been shown in the research to support metabolism. In addition to weight loss, individuals saw improvements in insulin resistance, high blood pressure, cholesterol, and triglycerides. However, these were only short-term studies. The long-term effects of remaining on a ketogenic diet have not been studied, and experts suggest the high fat nature could in fact be detrimental to longevity.

Interestingly, it has been researched for neurological-related conditions. It first came about in the 1920's as a tool to treat epilepsy. Newer research suggests it may be an efficient tool to treat those with autism. Again, much more research is needed.

What are the downfalls?

It’s not as easy as it sounds to get into nutritional ketosis. Factors that can affect ketone production include resting metabolic rate, body mass index, body fat percentage, efficiency of carbohydrate use and deprivation, and protein intake. It may take several days after beginning a carbohydrate restriction to reach a state of ketosis, and during this time dieters may experience nausea, vomiting, headaches, and fatigue. This is known as the keto flu and may last for a few days to a few weeks after someone begins the diet.

Additional risks of eating this way include:

• Nutrient deficiencies

• Liver problems

• Kidney problems (such as kidney stones and spilling protein in the urine)

• Constipation

• Brain fog

• Mood swings

• Osteoporosis.

As such the ketogenic diet is not recommended for people with diabetes, those who take insulin or oral diabetes medications, pancreatitis, liver failure, disorders of fat metabolism, and carnitine deficiency.

In addition, if not done carefully, it is possible for the body to enter a state of ketoacidosis. This is when too many ketones are produced and the pH of the blood changes. While more common in diabetics, it is possible for non-diabetics to experience this on a keto diet. This is a life-threatening condition in which emergency medical care is required.

Bottom line

This diet may be therapeutic in treating epilepsy and other neurological conditions, and has been shown in the short-term to support weight loss. Because it is extremely high in fat, including saturated fat, and long-term safety data is lacking, it is not recommended to practice this diet over a long period of time. If you do want to try it, work closely with your doctor and a dietitian to ensure that it is done safely and in an established time frame, with a strict end date.

References

Harvard T. H. Chan School of Public Health. (n.d.). Diet Review: Ketogenic Diet for Weight Loss. Retrieved from https://www.hsph.harvard.edu/nutritionsource/healthy-weight/diet-reviews/ketogenic-diet/

Masood, W., Annamaraju, P., Uppaluri, K. R. (2022). Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK499830/#_NBK499830_pubdet_

Should you try the keto diet? (2020, August 31). Harvard Health Publishing. Retrieved from https://www.health.harvard.edu/staying-healthy/should-you-try-the-keto-diet