by Matt Worthy

The Keto Diet Explained

The “keto” diet seems to be the “it” diet of the moment among health and fitness devotees. But what is a keto diet? A keto diet is short for a ketogenic diet. A ketogenic diet is a diet that causes the body to enter a state of “ketogenesis.”  Ketogenesis refers to the process that occurs when fatty acids are broken down within the liver into a group of substances known as “ketone bodies”. The names of these ketone bodies are acetone, beta-hydroxybutyrate, and acetoacetate. Ketone bodies are typically only produced when the body’s normal fuel source, carbohydrates (or glucose), is “so scarce that energy must be obtained from the breaking down of fatty acids.” 1 In other words, the body is burning fat for fuel, instead of glucose.

The benefits of a ketogenic diet are touted as burning “more fat for fuel at a given instensity”, obtaining “a more stable blood sugar”, recovering “faster from your workouts – keto is anti-inflammatory”, and attaining “a higher degree of mental clarity”. 2 In general, to get into a state of ketosis, “a carbohydrate intake below 50 [grams] is required”. 3 However, many ketogenic diet advocates suggest a target of 20 grams of carbohydrates per day or less. The vast majority of calories consumed in a ketogenic diet come from healthy fats. MCT (medium chain triglyceride) oil and coconut oil, for example, are staples and topics of frequent discussion within the ketogenic community.

When ketone bodies are being produced, a person is said to be in a state of “ketosis”. Ketone bodies can be used by the body for energy in lieu of the body’s normal energy source, glucose. Since ketone bodies are down-regulated from stored body fat, ketosis can result in a relatively rapid loss of fat.

The ketogenic diet consists of:

  • Natural fats: butter, olive oil and nut butters are all keto friendly and this type of food should be the main source of your calories. Use these fats to cook your food and garnish dishes with high fat sauces or garlic butter.
  • Meat: grass-fed beef and pasture-raised poultry and pork is best – the higher the quality the better. Note: a keto diet is generally considered to be a moderate protein diet. Too much protein can result in “gluconeogenesis” or the conversion of substances like protein to glucose. 4
  • Dairy products: Eggs, cheese and full cream are all part of the keto diet. The higher the fat the better. Milk should also be used sparingly due to sugar content. Realize that many within the keto “community” avoid dairy entirely due to food sensitivity issues.
  • Vegetables: A staple part of a keto diet, vegetables will play a major part in a keto based menu; they will replace the pasta, rice and potato dishes. Choose vegetables that are grown above ground as they contain fewer carbs. Spinach, avocado, broccoli, cauliflower and other low carb vegetables can be used to replace traditional dishes. Cauliflower especially can be utilized as mash or a rice substitute.
  • Nuts: Use sparingly as a snack and choose macadamia and pecans for their fat content.

Foods to avoid:

  • Sugar: It seems obvious, but all items containing sugar should be avoided. Soft drinks and sweets, breakfast cereals and pastries should be dropped from the diet.
  • Starch: Bread, pasta, rice and muesli all contain starch. Whole meal products are not better or acceptable – they are just less harmful. Root vegetables and legumes are also best avoided if an extremely low carb regime is being followed.
  • Fruit: Nature’s candy! Unfortunately, fruit is full of sugar and harmful to a keto diet. It should only be consumed as a treat and in small amounts.

Drinks:

  • Water: The perfect accompaniment to keto food. Due to symptoms that may be experienced, it is imperative to keep hydrated.
  • Coffee and Tea: Taken black or with cream is best.
  • Beer or Wine: Beer is definitely not included in a keto diet. It is the equivalent of drinking bread. If alcohol is drunk, it should be dry white wine or spirits without harmful sugary mixers.

The key element to a keto diet is low carb but not no carb. The replacement of carbs with fat also needs to be monitored. How much fat does the dieter need to supply the body with sufficient amounts of fat? One study suggest that, especially for athletes on a keto diet, fats should be consumed ad libitum (or as much as you want). 5 Keto dieting involves discarding traditional dietary “rules” and encourages the consumption of natural fats until full. Hunger is not a component of the LCHF diet (Low carb high fat).

Achieving Ketosis

There is no research that shows the exact amount of time to achieve ketosis as all of our bodies are different. There are some key signs that indicate the body has achieved the ketogenesis

  • Dry mouth: Constant craving for water is a key sign of ketosis and should be taken seriously. Hydrate regularly and keep water close by for regular intake.
  • Ketosis Breath: There are a combination of ketones that can lead to bad breath when the body reaches ketosis. Acetone, beta-hydroxybutyrate and acetoacetate combine to create this form of halitosis. While this is unpleasant for others, it is a sure sign that ketosis has been achieved.
  • Ketosis Influenza: Withdrawal from carbs can cause the body to undergo a series of symptoms that resemble flu. Coughing, severe nausea and fatigue can make the sufferer feel they are in the throes of a flu like disease, but they are not contagious, and the symptoms will pass in a matter of days.
  • Insomnia: Lack of sleep is also a common side effect when carbs are discarded by the body. Low levels of serotonin induced by ketosis can cause sleepless nights for some.

There are also tests that can indicate ketosis and are used to measure the three types of ketones.

  • Urine strips: These are used to measure acetoacetate and consist of a stick that should be urinated on.
  • Blood meter: Used to measure beta-hydroxybutyrate, a small amount of blood should be placed on the stick and the machine measures the levels. This method is more accurate than the urine tests.
  • Breath meter: Convenient and suitable for those with an aversion to bodily fluids, the amount of acetone in the breath can indicate ketosis.

Examining the Evidence

The James Madison University carried out a study that examined the benefits of a low-carb diet combined with a six-week period of CrossFit training and how it affected the composition of the body and performance. The participants in the study ranged in age and fitness. The subjects were taken off any performance enhancing supplements a week prior to baseline testing.

Subjects were assigned a diet protocol depending on their body mass index and were required to keep accurate records of their dietary intake. The training protocol required four CrossFit training sessions per week. The results were collected after each class. The subjects were prevented from participating in any other high energy physical activities throughout the six-week study. The subjects were monitored carefully, and the results showed that adhering to a LCKD (low carb keto diet) can lead to weight loss and improve body composition. The results also indicated that combining a keto diet with CrossFit training could be a successful method of weight loss for all levels of age and fitness. The study concluded “significant decreases” in percent body fat, fat mass, weight, and body mass index all while maintaining lean body mass and improving total performance and power. 6

The evidence on ketogenic diets is mixed. A study published in 2016 by the American Journal of Clinical Nutrition examined a group of obese men by placing them first on baseline, relatively high carbohydrate diet. After four weeks on the baseline diet, the men then spent four weeks on a ketogenic diet. At the conclusion of the study, the researchers noted that the ketogenic diet was “not accompanied by increased body fat loss.” 7 A different study from 2016 published in the journal Endocrine found that a very low-calorie-ketogenic diet induced a greater reduction in body weight, waist circumference, and body fat mass than a low-calorie diet and was still effective 24 months later with a decrease in visceral adipose tissue and a reduction in disease. 8

The Verdict

So the verdict is … the ketogenic diet can be a great option for some people. However, it is not the holy grail of dieting. Different people have success on many different types of diets. The best diet is going to be the one that you can stick to long term that results in a healthy weight and a healthy metabolism for you.

References

  1. Chaudhuri, J. Ketone Body Metabolism. [cited 2018 4/18/2018]; Available from: http://www.srmuniv.ac.in/sites/default/files/files/KETONEBODYMETABOLISM.pdf.
  2. Roberts, M.W., Tommy. The IRONMAN Guide to Ketosis. 2017 3/12/2017 [cited 2018 4/18/2018]; Available from: http://www.nourishbalancethrive.com/blog/2017/03/12/ironman-guide-ketosis/.
  3. Willett, B. The Advantages and Disadvantages of Ketosis. 2017 10/3/2017 [cited 2018 4/18/2018]; Available from: https://www.livestrong.com/article/492485-the-advantages-disadvantages-of-ketosis/.
  4. Benson, D. Gluconeogenesis. 2018 2/28/2018 [cited 2018 4/18/2018]; Available from: https://chem.libretexts.org/Core/Biological_Chemistry/Metabolism/Anabolism/Gluconeogenesis.
  5. Paoli, A., A. Bianco, and K.A. Grimaldi, The Ketogenic Diet and Sport: A Possible Marriage? Exerc Sport Sci Rev, 2015. 43(3): p. 153-62.
  6. Gregory, R.M., A low-carbohydrate ketogenic diet combined with six weeks of crossfit training improves body composition and performance, in JMU Scholarly Commons. 2016, James Madison University. p. 72.
  7. Hall, K.D., et al., Energy expenditure and body composition changes after an isocaloric ketogenic diet in overweight and obese men. Am J Clin Nutr, 2016. 104(2): p. 324-33.
  8. Moreno, B., et al., Obesity treatment by very low-calorie-ketogenic diet at two years: reduction in visceral fat and on the burden of disease. Endocrine, 2016. 54(3): p. 681-690.