What is Ketosis and Why Try a Ketogenic Diet?
Carbs are an energy source. It’s one of the reasons we eat fruits to boost energy or cereal for breakfast. It’s the philosophy behind ‘carb loading’ to store energy in the muscles and liver for an athletic event. It’s the ‘Intro to Metabolism’ lesson in biology that explains how your body uses glucose to produce the adenosine triphosphate (ATP) that your tissues need to function.
However, the human body is rather amazing and can turn other nutrients into usable energy as well. Our bodies are perfectly capable of breaking down fats to give your tissues all the energy they need. This ‘fat into fuel’ metabolic pathway is known as ketogenesis and subscribing to a ketogenic high fat diet can have some impressive health and performance benefits.
Now, based on the long-standing high carb government prescribed nutrition guidance, a high fat ketogenic diet might sound completely backwards and it very much is opposite to traditional dietary teachings. One forgoes the standard model of high carbs (grains, rice, pasta) with plenty of fruits and veggies for a high fat diet of avocados and bacon . . . and yet expects to be healthy?
Absolutely—and there is evidence to prove it. It all boils down to how your body reacts to a ketogenic diet and the resulting benefits it brings to both your brain and body.
Energy from Carbs vs Energy from Fats
When you consume carbohydrates, your body breaks them down into glucose which is metabolized to form ATP. Those ATP molecules are then used by your tissues to handle their respective physiological tasks. There are several processes within your cells that handle this conversion.
The up side to carbohydrates is usually fast and easy energy, but it can also come with its downsides. In our carb obsessed civilization, grains and sugar are everywhere. Over-indulgence and the resulting prolonged elevated blood sugar can lead to a whole host of issues from insulin resistance to inflammation, metabolic syndrome, and more.
When your body isn’t provided with enough dietary carbs it begins to use up your stored glucose (glycogen). Once that is used up, it looks for somewhere else to get that energy—and it finds it in fats. Your body will break down your fatty tissues into free fatty acids that are taken to your liver. From there, it breaks down these fatty acids to produce acetyl-CoA and ketone bodies which your tissues can then use for energy in the absence of glucose.
What is a Ketogenic Diet?
Given the opportunity, your body is always going to default to carbohydrates for energy. That means in order to achieve ketosis, one needs to cut out the carbs. A ketogenic diet is one that switches your body’s primary source of energy from carbohydrates to fats. This happens by restricting carbs to the point that your body opts to break down fatty acids instead— typically to a level below 50g of carbs per day. A ketogenic diet typically requires a split of 70-75% of total daily calories from fat sources, 20% from protein and less than 10% coming from carbs.
But is your body truly capable of producing enough energy just from fats? Yes—in fact, beta-hydroxybutyrate (BHB) which is one of the primary ‘ketones’ generated from the breakdown of fats for fuel, provides more energy per unit of oxygen than the glucose your body derives from carbs.[1] This is good news for energy-hungry organs like your brain, especially considering that BHB easily crosses the blood brain barrier. But the benefits don’t end at energy production.
Benefits of Ketosis
Weight Loss
It might sound counter-intuitive to consume fat in order to lose fat. But it’s the reliance on fat for energy that helps break down the fat stores within your body. Since your body recognizes it needs fat for energy, it will readily seek excess fat stores and break them down for sustenance. There may actually be several mechanisms at play that contribute to healthy weight loss on a ketogenic diet.[2] These include:
- Appetite control resulting from a combination of feeling fuller on increased fats, effects on appetite-related hormones, and the potential role of ketone bodies in supressing hunger.
- Reduction in the creation of fat and fat stores while increasing the breakdown of fats in the body
- Increased metabolic efficiency by decreasing carbon dioxide production
- The increased energy cost of using proteins to fill the gap for necessary glucose in the body (gluconeogenesis)
A major problem with diets that restrict calories is the hunger that comes along with it. Ketogenic diets tend to alleviate that hunger simply through your body’s natural physiological response. That makes ketogenic diets a great option for those struggling with their weight loss goals. It is important to note however, that although a ketogenic diet does trigger more rapid utilization of fat for energy, an overall caloric deficit is still required for fat loss.
Cholesterol & Cardiovascular Disease
One in every four deaths in the United States is from heart disease.[3] Sugar is a primary culprit for elevated cholesterol and metabolic disorders such as metabolic syndrome and type II diabetes.[4]
Evidence has shown that reducing carb intake to the level of ketosis improves blood lipid profiles.[2] Not only does this apply to your triglycerides, but it decreases total cholesterol while increasing the ratio of HDL (the good cholesterol). It has also shown to be able to better manage your LDL (bad cholesterol).
Brain Health
Your brain is a big, complex organ that requires a lot of energy. Ketone bodies not only provide more efficient energy production, but many report increased mental clarity while on a ketogenic diet. There could be several reasons for this, one of them being the resulting mitochondria increase in brain cells.[1] Ketones also act as an antioxidants by increasing the activity of glutathione peroxidase. This enzyme combats reactive oxygen molecules linked to aging and neurodegradation.[1]
Ketogenic diets have been demonstrated to have some therapeutic benefits for several neurological conditions including: headaches, brain trauma, sleep disorders, Alzheimer’s and Parkinsons’ disease.[2] It seems strange for such a simple shift in diet to affect so many different diseases. However, many neurological disorders boil down to abnormalities in cellular function. Though the mechanisms are still being discovered, it may be that by raising ATP and acting as an antioxidant in neurological tissues, ketone bodies keep brain cells healthy and better able to fight off the root cause of these conditions.
This is not a comprehensive list and the benefits of a ketogenic diet continue to be uncovered daily it seems with expanded research efforts. Ketogenic dieting is not a new idea, it’s been around for decades and doctors have implemented the diet therapeutically for specific conditions like epilepsy for many years. But as we continue to learn more about the potential harmful role that over-ingestion of sugars plays in the North American diet and food supply, it is worth revisiting the benefits that ketosis can have on the brain and body. The evidence points to ketogenic diets as a simple dietary approach to combating some of the issues that are prevalent in our population: obesity, heart disease, and brain related ailments.
Sources
[1] Fan S. (2013-10-1) The fat-fueled brain: unnatural or advantageous? Retrieved from www.scientificamerican.com
[2] Paoli A., Rubini A, Volek JS, & Grimaldi KA (2013) Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets. European Journal of Clinical Nutrition 67:789-96
[3] https://www.cdc.gov/heartdisease/facts.htm
[4] Gunnars K (2013-9-30) 10 Disturbing Reasons Why Sugar is Bad For You. Retreived from www.authoritynutrition.com