In order to explain how keto diet works, you must first understand the basic workings of the body’s metabolism.
Our body has two opposing biochemical pathways promoted by the peptide hormones- insulin and glucagon. Think of them as the yin and yang of your metabolism, where the goal is to balance your blood glucose levels to maintain availability of energy for your body’s cells.
Insulin’s job is to lower blood sugar levels; it does this by promoting the uptake of glucose into cells. Once glucose is absorbed into cells it can undergo glycogenesis or lipogenesis.
Glycogenesis is the process by which glucose absorbed by cells is converted to the polysaccharide glycogen and lipogenesis is the process by which glucose is converted to triglycerides.
In other words fat glycogenesis occurs in skeletal muscles and lipogenesis occurs in fat cells and both of these processes occur in the liver.
Glucagon’s job is the opposite of insulin’s. It raises blood sugar levels by promoting glycogenolysis and gluconeogenesis in glucose analysis. Glucagon binds receptors in the liver the liver cells then convert glycogen to glucose and release it into the blood.
An average person’s glycogen stores can last about 12 to 14 hours or 2 hours of moderate exercise. This is maintained via the ingestion of about 250 to 400 grams of carbs. Daily glycogen stores run out during prolonged exercise; hence the feeling that you hit a wall and can’t keep going.
It can also be depleted during fasting low carb diets or with untreated type-1 diabetes.
Gluconeogenesis is the term for the metabolic pathway in which glucose is generated from non-carb sources like glycerol which are components of fat or from glucogenic amino acids.
Amino acids are components of proteins. Fasting can cause your cells to start breaking down protein in order to release amino acids into the bloodstream. The glucogenic amino acids can be converted to glucose in the liver. A major source of protein is your muscle mass which is why people are warned that fasting can result in the wasting away of muscles.
There is also another category of amino acids- ketogenic amino acids. These can be converted directly into Acetyl-CoA, the precursor of ketone bodies.
Unlike fat, glycogen can be mobilized rapidly in skeletal muscle and utilized as a fuel source without the presence of oxygen. When you consume carbs they get converted into glucose which floats around and is particularly important to brain function.
Meanwhile fat oxidation or burning requires the input of energy. Triglycerides are the major fat in our bodies and in our food. A triglyceride consists of three fatty acid groups attached to a glycerol via an ester bond. Hence fatty acids are subunits of fat-molecules.
During lipolysis, the ester bond between the fatty acids and the glycerol is cleaved. The fatty acids are removed from the fat cells to float in the bloodstream. This process is triggered by high levels of glucagon, which occurs as a result of low-blood sugar.
Triglycerides can enter most of the body cells; exceptions being red blood cells due to their lack of mitochondria and the central nervous system due to the blood-brain barrier. Enzymes then catalyze reactions to convert the fatty acids to Acetyl-CoA which can then enter Kreb cycle.
Kreb cycle, also called the citric acid cycle, is a series of biochemical reactions that oxidize Acetyl-CoA to release energy.
Ketone bodies get produced by the liver when it breaks down fatty acids and the emanates amino acids in the absence of carbs and glycogen. Hence, ketone bodies are present during intense gluconeogenesis.
Ketone bodies include acetoacetate, beta-hydroxybutyrate and acetone which is a spontaneous breakdown product. They are easily taken up by cells of other tissues.
For instance the brain, unlike glycerides ketone bodies, can pass the blood-brain barrier and replace glucose as the brain’s energy source. They then get converted to Acetyl-CoA which can enter the kreb cycle.
Let’s move on to our next phase and understand how keto diet works on our body.
How Keto diet works on our body?
In the ketogenic diet, the goal is to switch from a state of glycolysis, where your body is burning glucose, to a state of ketosis, where your body is burning ketones. In plain English, you are forcing your body to start burning your fat as its main energy source, instead of incoming carbs.
This is accomplished by making one’s food intake high in fat with moderate protein and almost no carbohydrates. The body soon runs out of its preferred energy source (carbohydrates) and begins to burn fats instead.
On this diet, the aim is generally for carbs to make up about 5% of macronutrient intake, while protein intake is 15 to 30 percent and fat intake is the rest. It takes several days for your body to adapt to the change in macro nutrient composition.
Side effects during Keto Diet
Now that you know how keto diet works, let’s talk about what side effects are associated with Keto diet.
Over the first few days on the keto diet, the body enters a state of ketosis and insulin levels drop rapidly, while ketone bodies increase. Many though not all people, experience the keto flu phenomenon.
During this time, this is caused by the rapid loss of water that has been retained in the water along with the carbs from the previous diet. Along with this water there is a massive loss of electrolytes including sodium potassium and magnesium. Symptoms are thirst, frequent urination, fatigue, muscle cramps and headaches, nausea and mental fog.
For many people taking supplements or consuming pickle juice for the lost electrolytes and drinking plenty of water makes their Keto flu go away faster. Once the keto flu has been overcome, many people report improved mental clarity energy levels and decreased appetite.
Some people use the keto diet for its weight loss. Potential weight loss is very rapid in the first few days due to water loss afterward weight loss slows down but stays linear.
A study has shown that athletes on the ketogenic diet burn significantly more fat during a workout.
Many people go on ketogenic diets to increase mental clarity.
Another side effect of the ketogenic diet is breath smelling fruity or like nail-polish which comes from the ketone bodies. The smell comes from the spontaneous decomposition of one of the ketone bodies- Aceto-acetic acid into acetate.
Many report that the side effect goes away after being on the diet for a while.
Kudos, you have learned everything about how keto diet works, if you want to give it a try, please read this next article on how to get started: https://myhealthycollection.com/keto-diet-beginners-guide/