The Truth About Keto
Updated: Jul 29, 2019
Here’s everything you need to know about keto – what it is, how it works, if it's safe, and why there is a diet made specifically to exclude carbohydrates (FYI: CHO = carbohydrates)
Let me start off by saying that there is not one "diet" that is better than another. Everyone’s body is different with it's own individual, unique needs. Your body burns a specific number of calories per day. To lose weight, you need to consistently consume less than what you burn. To gain muscle mass, you need to consume more. To maintain your body weight, you need to consume the same amount of calories as you burn.
What is Keto?
A keto diet is very low in carbs, high in fat, and moderate in protein. A typical keto diet ranges from 20-40g of CHO per day, max. The DRI (Dietary References Intake) of CHO for men and women is 130g per day. 130g per day is based on the average minimum amount of glucose (CHO) the brain uses each day. So essentially 3-6 days on a typical keto diet will equate to 1 day of the DRI CHO intake. The National Academy of Sciences developed the AMDR (Acceptable Macronutrient Distribution Range) and recommends that CHO make up 45-65% of your total daily calories. Based on a 2,000 calorie diet, that would result in 225-325g of CHO per day. This range is based on scientific evidence suggesting that this percentage decreases the risk of chronic diseases and prevents essential nutrient deficiencies.
Clearly, CHO are important. They are a good source of fiber, fuel most exercise activities, and some nerve cells in the brain, eyes, & red blood cells are entirely dependent requiring a constant source of glucose (CHO). For a longer list of CHO functions, click HERE.
Ketones are normally produced in the body in small amounts, but ketone levels increase in periods of fasting, diabetics, and high-fat diets.
Keto is short for ketogenic which refers to a metabolic state called ketosis. The body needs glucose to burn fat efficiently, so when CHO are not readily available, the liver cannot break down fat completely. So instead, it produces small compounds called ketone bodies. Ketones are metabolic by-products (think leftovers) of excess fatty acid metabolism. Ketone bodies can serve as an energy source in most cells and are critical during fasting and starvation situations.
Ketones are normally produced in the body in small amounts, but levels increase in periods of fasting, diabetics, chronic alcoholics, and low-carb diets. Too many ketone bodies can result in ketoacidosis. Ketoacidosis means that the body cannot properly regulate ketone production or ketones are being produced quicker than the body can use them, creating a build up of ketone bodies in tissues and fluids. The accumulation commonly causes dehydration and substantially decreases the pH of the blood (making the blood increasingly acidic). In extreme cases, coma or death may result. To prevent this risk, an absolute minimum of 50-100g of CHO per day is recommended.
Why is this low-carb // high fat diet so popular?
When CHO intake is too low (AKA not eating enough CHO in the daily diet) to maintain blood sugar levels and to support the CNS (Central Nervous System = brain and spinal cord) then gluconeogenesis occurs. Gluconeogenesis is when the body forms new glucose from proteins and fats. First the body will use protein in body tissues to form new glucose. 1g of protein results in 0.56g of glucose. Then the body will turn to fats to form new glucose. Once in the body, fats break down to fatty acids and glycerol. Glycerol can be converted to glucose via gluconeogenesis in the liver. 1g of glycerol results in 1g of glucose.
Glycerol (coming from fats) yields a greater amount of glucose than protein, which is why keto diets are typically high in fat. This is the basic reasoning behind the keto diet; your body will burn stored fat as energy due to the extremely low CHO diet. That sounds like a dream come true, right? Maybe, maybe not...
Fat is the main energy source at rest and during low-intensity exercise. As the exercise intensity increases to moderate / high, CHO become the main energy source. The switching from fat to CHO as the fuel source is called the crossover concept. This occurs at about 65-85% of a person's working capacity.
Exercising on a Keto Diet
If you workout regularly, keto could do more harm than good. When CHO intake is too low and protein stores are used as the main fuel source, that protein is coming from your muscle tissues AKA muscles that you work so hard for in the gym. You'll essentially be burning your muscle mass during your workout, not fat.
As exercise intensity increases, so does the need for CHO. Compared to fats, CHO are available as an immediate energy source. Why? Because they're stored in muscle cells. Fats are stored in remote sites in the body (subcutaneous fat = under the skin | visceral fat = around the organs). If fats need to be used for energy, they need to travel through the bloodstream to the muscles to be used.
CHO can be used as an energy source for short periods of intense exercise without needing oxygen. Fats cannot. When CHO are metabolized by the body, they require less oxygen yet produce more ATP (energy) than fat. (Per unit of oxygen consumed, glucose/CHO produces 2.7 ATP while fat produces 2.3 ATP)
Regular exercise increases the muscles ability to store and use CHO for energy AKA when you exercise regularly, your body processes CHO more efficiently. Consuming CHO after exercising can help restore blood glucose levels, replenish muscle/liver glycogen, and prevent DOMS (Delayed Onset Muscular Soreness = the soreness you feel a couple days after working out).
An enhanced sympathetic nervous system can lead to poor recovery, anxiety, irritability, decreased quality of sleep, fatigue, nervousness, and more.
Studies show that the sympathetic nervous system is enhanced after only 3 DAYS of reduced CHO intake (think of a keto diet). An enhanced sympathetic nervous system can lead to poor recovery, anxiety, irritability, decreased quality of sleep, fatigue, nervousness, + more.
If you workout at a moderate/intense level regularly, keto may not be for you. Ketones may be used by the muscles, but they do NOT appear to significantly contribute to energy production during exercise. If you do NOT workout, a proper, short-term keto diet may work for you.
Does keto work?
Keto diets have been found to be beneficial for some individuals if it's used for short periods of time; no longer than 2 weeks. Very low calorie/low carb diets can be helpful in regards to losing weight quickly and adjusting blood sugar levels for those who are obese or diabetic.
Those on the keto diet lost more weight initially, but for the overall duration of the diet, there were no significant weight loss differences.
Studies compared a keto diet to a balanced diet (AMDR % of protein, CHO, and fat). Those on the keto diet lost more weight initially, but for the overall duration of the diet, there were no significant differences in weight loss.
Low calorie/low carb diets have a laundry list of negative effects = lack of energy, weakness, headaches, nausea, GI distress, decreased blood volume, inflammation of intestines and pancreas, decreased heart muscle tissue, decrease in HDL (good cholesterol), micronutrient (vitamin & mineral) deficiencies, + more.
High-fat diets over a long period of time can lead to a higher risk of serious medical conditions; atherosclerosis (plaque build up in the arteries), heart attack, coronary heart disease, high blood pressure, obesity, + more. The National Academy of Sciences indicated that both very high-fat AND very low-fat diets may be a predisposition to coronary heart disease which is the #1 cause of death in industrialized countries.
A diet balanced in CHO, protein, and fat is not only just as good as weight loss, but it is better for your overall health and wellness in the long-run.
When it all comes down to it...
We NEED carbohydrates. Our bodies physiologically need them or else CHO wouldn't be one of the 3 macronutrients (carbohydrates + protein + fats). There are some benefits to keto diets, but it is dependent on the person, their health history, and the length of the diet. I personally think that when people see results from a keto diet, it is because the carbs being cut out are simple carbs that are processed, filled with sugar, and lacking in nutrients. It's not physically or mentally healthy to deprive yourself of a certain food as the keto diet does. If you go cold turkey and cut something out, you are going to want it more, it's human nature. I encourage you to educate yourself in basic nutritional needs or choose a certified coach (hey, hi pick me!) to show you what your body needs and make sure you're eating the correct amount of carbs, fats, and protein.