Is the ketogenic diet suitable for athletes?

 Article originally published on www.holy-fat.com/

Can fueling with fat optimize your performance? How can you keep going without sugar?

Holyfat explains the principle of the ketogenic diet and helps you understand how fat can become your preferred fuel for achieving your athletic goals!

First, what is the ketogenic diet?

 Used for more than 90 years, particularly for therapeutic purposes (for epilepsy, diabetes, or cancer, for example), the ketogenic diet is based on a simple principle: drastically reduce carbohydrate intake in the diet so that fats take the lion’s share.

 When you wake up in the morning after a good night’s sleep, having eaten your plate of pasta the previous evening at 7 p.m., your meal is a distant memory and your blood sugar level is low. To prevent you from running out of steam before the next meal and to reserve glycogen use for cells that cannot do without glucose, several metabolic pathways become active.

Ketogenesis is one of them; it enables the production of ketone bodies in the liver from fats stored in our adipose tissue. These ketone bodies are used by muscle cells, organs, and neurons. They are the preferred fuel source for the renal cortex and heart and can provide, during prolonged fasting, up to 75% of the energy consumed by the brain (glucose reserves in the form of glycogen in the liver or muscles provide the remaining 25%).

The ketogenic diet therefore takes its name from this metabolic pathway, which allows the body to use fat as an energy source instead of carbohydrates.

Okay, but what’s the point of following this diet if my body adapts anyway?

Let’s make a quick comparison between what happens in someone who eats “normally” and someone who follows a ketogenic diet

Yes, you might think all you have to do is eat your pasta and go run your marathon; the ketone bodies will take over anyway. Yes, but no—it’s not that simple! Nature is well designed, but it isn’t an all-you-can-eat buffet either. 

In reality, we need to look at what happens when your body primarily runs on sugar, that is, as part of a so-called normal diet (with 40 to 55% carbohydrates in your intake).

Situation A: So-called normal diet, the balanced diet recommended by ANSES 

After your meal, your blood sugar will rise. The more carbohydrate-rich the foods it contains, the more your blood sugar will increase. Add to that a food’s ability to raise your blood sugar, known as the glycemic index (GI). A meal rich in high-GI foods and low in fiber, fat, and protein (for example: fruit juice, baguette, honey, or before a race, a sports nutrition product such as a gel) will send your blood sugar soaring very quickly. But it will also fall just as quickly, and that’s when you run into trouble if you don’t have refueling supplies within reach: sweating, palpitations, dizziness, nausea, trembling, intense fatigue… Hypoglycemia is watching you, Huguette!

This is even more true during sports because energy expenditure is multiplied, with the effort being much more intense for our bodies. We are no longer cruising; we need to stoke the furnace to keep the engines running (can you picture the Titanic too? Poor Jack… but that’s another debate). This is why, when you start consuming a gel, fruit paste, or sports drink, you need to take more every 45 minutes, otherwise watch out for an energy slump. But when you run or cycle for hours and have to constantly recharge the battery with sugar, hello nausea and goodbye intestines.

Let’s return to your blood, flooded with glucose after a meal. Your pancreas will release insulin, the hormone responsible for regulating this sugar level, so that glucose can enter the cells that need fuel (and also prevent your blood from turning into syrup). The excess will be synthesized into glycogen in the liver and muscles (through glycogenesis) to create glucose reserves; the rest will be converted into triglycerides and stored in your fat cells through lipogenesis (literally, the production of fat). Note that as long as your cells have sugar available, you will not draw on your fat reserves to continue the effort… In other words, if you exercise to lose your belly, this is not the best method!

These famous fat reserves will be used during fasting while at rest, completing the cycle. During exercise, however, the body does not have time to adapt; it needs energy immediately to maintain the pace, so you must refuel frequently to continue your competition or training. 

Situation B: Ketogenic diet, fat, fat, and more fat

During a ketogenic diet, you consume 80% fat, protein, and a tiny amount of carbohydrates—the bare minimum. Note that, unlike protein or fat, carbohydrates are the only nutrient that is not essential in large quantities, since our bodies are capable of synthesizing them (they are still necessary for our red blood cells and neurons and should not be eliminated completely, of course).

Your body will therefore be deprived of carbohydrates for an extended period, not merely a few hours. It will then gradually enter what is known as a state of ketosis. Ketosis is when the body switches fuel sources, moving from glucose to ketone bodies. The few grams of sugar remaining each day are therefore intended for our glucose-dependent cells, which cannot use ketone bodies as fuel. Someone starting a ketogenic or LCHF diet will take approximately 2 to 3 weeks to enter this state of ketosis. They will also go through several phases that are not necessarily pleasant at first, while the body gets used to the change and withdraws from sugar: fatigue, nervousness, nausea, …

Once this period has passed, the transition will be complete and the individual, now “keto-adapted,” will naturally use fat as fuel rather than carbohydrates! They will then feel full more easily and have more energy, since they will no longer be subject to blood sugar fluctuations (so goodbye to the 11 a.m. slump, the 4 p.m. hunger pangs, and the urge for chocolate in front of the TV). They will often lose weight, since they will draw on their fat reserves to provide energy to their muscles and organs.

It should be noted that a new trend is emerging, known as “Metabolic Flexibility.” We’ll discuss it in a future article; let’s just say it’s the next step, once you are fully keto-adapted and still want to reintroduce some carbohydrates.

The ketogenic diet and sports

You are beginning to understand the benefits of a ketogenic diet, but you do not feel ready to follow one nonetheless, because it is true that it is quite drastic and requires a complete reorganization of your eating habits.

Is it therefore worthwhile to consider fat solely in the context of sports?

Yes, indeed. First, let’s compare the composition of a sugary gel with a good-fat snack—Holyfat, for example (okay, that may not sound very objective, but we are the only ones in France offering this type of product, so we don’t really have much choice in the end; it’s not my fault, as Lolita would say).

In your generic-brand gel, you have an average of 70% carbohydrates, often in the form of glucose syrup and maltodextrin, less than 0.5% fat, and less than 1% protein. The rest is water, salt, and a few milligrams of vitamins and fatty acids. For a pouch of approximately 30 g, you get the equivalent of 90 kcal of energy.

At Holyfat, we work on the basis of the ketogenic diet. Our product contains 70% fat (and good fats: nuts, almonds, MCT oil), less than 3% carbohydrates (naturally found in the nuts) and 20% protein. A 28 g pouch provides an average of 200 kcal, twice as much as a gel for the same quantity, without causing any blood sugar fluctuations. A good, steady dose of energy that lets you keep going for a long time without hunger pangs or an energy dip.

Indeed, even if you are not keto-adapted, consuming fat before and during your outing instead of sugar will protect you from any blood sugar fluctuations and enable you to last the distance and duration with the energy you had during the first few miles! We nevertheless recommend keeping a source of carbohydrates within reach and consuming it during the final hour of exercise to give you one last lifesaving boost before the finish line (and replenish your glycogen stores). Of course, all these nutritional experiments should be carried out during training, not on competition day, since everyone has their own reactions and habits.

In a nutshell, good fat is life!

So don’t hesitate to consume it—daily if you wish to start a ketogenic diet, or during exercise, especially when it lasts a long time!

Note, however, that in certain physiological or pathological conditions (pregnancy, breastfeeding, insulin-treated diabetes, …), the ketogenic diet is not recommended. If you wish to start it, do not hesitate to seek help from your doctor or a dietitian to support and guide you through this dietary transition.

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