What is the keto diet?
The keto (short for ketogenic) diet is a diet which works on the principle of consuming very low amounts of carbohydrates, moderate amounts of protein, and high amounts of fat. The reasoning is that this distribution of macronutrients allows the body to use fat as its main source of energy. The body breaks down fat into ‘ketone bodies’ or ‘ketones’ in a process called ketosis. Some individuals use dip sticks to test for the presence of these ketones in their urine to assess whether their bodies have achieved ketosis.
A ketogenic diet can be prescribed under the supervision of a qualified dietician or doctor for the management of symptoms of individuals with medical conditions such as epilepsy, or type 2 diabetes. This blog post does not substitute for professional or medical advice, and thus if you feel as though a ketogenic diet would help you cope with certain medical conditions, you should seek the advice of a qualified medical professional. A ketogenic diet is often also adopted by relatively healthy individuals (those without chronic metabolic or other diseases) as a method for weight loss, due to the ‘fat burning’ properties. The diet has been shown to be effective in the short term in helping individuals lose weight, but we still do not know whether the diet will continue to remain effective and safe when employed over long periods of time.
How does it work?
It goes without saying that the body requires energy to be able to function, and it uses this energy in the form of glucose. Carbohydrates break down easily into glucose, making them an easy source of energy. When you begin exercising the body first utilises carbohydrates for energy. When these run out, the body needs to break down fat into glucose which it does through lipolysis and gluconeogenesis before it becomes usable. If you run out of fat stores your body will begin to burn muscle, which can lead to a condition called ‘rhabdomyolysis’, where the muscle breaks down and can cause damage to the kidneys. This medical condition can occur, for example, in a marathon or ultra-marathon runners who already have low body fat and do not consume enough carbohydrates during their race. Consuming high amounts of fat and low amounts of carbohydrates cause the body to primarily utilise fats for energy, as there are no readily available carbohydrates. By training the body to burn fat, individuals are able to increase the rate they lose fat mass.
In addition to attempting to train the body to burn fats rather than carbohydrates, the keto diet also allows people to feel satisfied for longer. Fat increases satiety (the feeling of being satisfied or full), and thus when you consume a diet high in fat, you are likely to feel more satiated. As the keto diet promotes the consumption of a large number of fats, individuals may feel fuller than they would on their normal diet and thus consume fewer calories overall throughout the day. You should be aware, however, that fat sources are high in calories, and thus it is still possible for you to create a calorie surplus which would lead you to gain weight.
Should I try it?
Whether you should try this diet or not is really a decision you should make with your health professional. It should be remembered that when you remove whole food groups (which in the case of the keto diet is carbohydrates) you miss out on whole nutrients. These can be supplemented where necessary, but this form of diet is difficult to sustain over a long term. For example, without eating the recommended amounts of fruit and vegetables, individuals miss out on their normal, healthy intake of fibre. This can lead to side effects such as constipation and other bowel issues (such as bowel cancer) due to the lack of fibre for long periods of time. Individuals may also become malnourished due to a deficiency in the important vitamins often found in fruits and vegetables, or risk osteoporosis from a deficit of calcium.
Your brain requires glucose to function properly. When people start the keto diet, they can often feel fatigued and groggy due to the lack of readily available glucose. This could affect individuals outside the gym, such as finding it difficult to focus at work, or in other situations such as driving. The process of obtaining energy from fat is slow, with fat oxidation generally used in longer, slower workouts. As fat oxidation is not a method of rapid energy production, individuals who perform high intensity and speed exercises will struggle to achieve the same performance they would on their regular higher carbohydrate diet. It may be a better idea to employ this method of dieting during your offseason when optimal performance is not as necessary and the focus may be on skills or body composition changes. Once it comes time for a competition, if your sport demands high-intensity performance, you may choose to switch back to a higher carbohydrate diet.