The Keto Diet & Your Performance

Nutrition Coach Joshua Smith explores what the ketogenic diet is, how it works and if it’s good for you

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The Keto Diet & Your Performance

What is keto? Is it just butter in your coffee? All the avocado and bacon you could want?

The ketogenic diet is a popular fad diet that promotes high-fat consumption with a low-to-moderate protein intake and minimal carbohydrates.

One positive to come from the keto diet is that it has taught people about the benefits of healthy fats and not to be scared of them. However, like with any ‘named’ diet, it is extremist, biased and unsustainable, in my opinion.

To start with, let’s explore healthy fats

In popular culture, the monounsaturated and polyunsaturated fats are what most people refer to as ‘healthy fats’. However, humans have consumed unprocessed forms of saturated fats such as organ meats from wild game, fatty fish, milk and coconuts for as long as we can trace back.

From this, the best definition we can devise of a healthy fat might be relatively unprocessed fats from whole foods.

Unhealthy fats, in comparison, are typically those that are industrially produced and designed to be non-perishable, such as:

- Trans-fatty acids that are present in processed foods
- Hydrogenated fats such as margarine (hydrogen is added to the fat chain to make a normally liquid perishable fat into a solid and shelf-stable fat)
- Most shelf-stable cooking oils (e.g. canola, soybean, corn oil, vegetable oils etc.)


Why do we need healthy fats?

We need adequate fat to support metabolism, cell signalling, the health of various body tissues, immunity, hormone production and the absorption of many nutrients including vitamins A and D. Having enough fat will also help you feel full in between meals.

There is also evidence to suggest that healthy fats help to alleviate symptoms of depression, improve cognitive function, preserve memory and serve as a slow-release source of energy, which can be used as fuel for low-intensity, steady-state exercise.

The ideal healthy fat sources to consume include fatty cuts of meat such as lamb, beef, organ meats and pork, fatty fish such as salmon, nuts, seeds, coconut oil, extra virgin olive oil and high-fat dairy products.


How does the ketogenic diet work?

The keto diet consists of 75% fats, 20% protein and 5% carbs. Yes, only 5% carbs. To give you an idea, that is around a fist-size of carrots or 10-15 grapes, FOR THE WHOLE DAY! As you can see, the keto diet is highly restrictive. You need to weigh and measure your food to ensure you are sticking to the guidelines to achieve ketosis. Ketosis is a metabolic process, something your body does to keep working. When it doesn't have enough carbohydrates from food for your cells to burn for energy, it burns fat instead. When on the keto diet you need to aim to consume less than 50g of carbohydrates per day.

A common misconception with this diet is people often think ‘going keto’ simply involves adding more healthy fats to your diet. This isn’t the case, which is why some people find they actually put on weight during the diet, because fats are calorie-dense. Simply adding fats to your current diet is a sure-fire way to achieve a calorie surplus which can lead to weight gain.

On the keto diet you also need to avoid too much of the following foods:
• Fruit
• Dairy
• Grains
• Beans
• Legumes
• Starchy vegetables such as sweet potato
• Sweet vegetables such as carrots or beetroot

Achieving ketosis can be beneficial for individuals with metabolic diseases, obesity, chronic inflammation, hypertension and brain disorders. However, obesity and inflammation can usually be reduced through weight loss by exercising regularly and eating a well-balanced diet consistently in a caloric deficit.


What about keto for athletic performance?

When it comes to high-intensity, strength, power and conditioning exercise; fats are not an optimal fuel source. Fats are slow-digesting and absorbing which has merit and benefits outside of a training window. Fats can slow down our use of carbohydrates for energy production and can also slow down the recovery process.

‘But I heard carbs are bad, why does it matter if we don’t have them?’

We need fuel to perform and carbohydrates are our primary source of fuel when it comes to exercise and maximal energy output. If you use fats as fuel, you are less likely to hit a wall because you don't have to worry about glycogen depletion. That sounds great but the problem with using fat as a fuel is you're not going to go as hard or as fast as you can when using glucose and carbohydrates. That said, fats can be used as a backup energy source when we do become depleted of glycogen.

You should also consider that you won’t gain any lean muscle on the keto diet as you won’t utilise insulin, an anabolic hormone, at beneficial times. If you’re in a weight-loss phase you won’t retain as much muscle due to the reduced amount of protein consumed.


The final word…

- Unless you're an ultramarathon runner, the keto diet won’t improve your performance (especially for CrossFit and functional fitness fans).

- Some evidence suggests that keto will benefit individuals with epilepsy and metabolic diseases. Outside of that, just consume healthy fats for the health benefits previously stated along with a caloric balance of protein and carbohydrates in a sustainable manner for your goals.

- If you are an active individual, focus on what your body needs to perform and recover. Good quality protein for muscle growth and repair, unrefined smart carbohydrates for fuel as well as for providing fibre and phytonutrients. Healthy unprocessed fats help to regulate hormones, reduce inflammation, improve cognitive function and sustain energy production.

- As healthy fats are calorie-dense, be cautious of your serving size. Aim for 1-2 thumbs per serve at each main meal. This can be increased on low-intensity/active recovery days and reduced on high-volume/high-intensity/double days of training.

To sum up, always be cautious of any ‘named’ diets and what they are restrictive of. The restriction is not sustainable. Unsustainable diets are the main problem with nutrition, health and fitness.

Consume a well-balanced diet of whole foods in a way that you enjoy. Focus on the purpose and role of all foods and consume them in a way that will help you work towards your health and fitness goals.

IMPORTANT INFORMATION: all content provided here is of a general nature only and is not a substitute for individualised professional medical advice, diagnosis or treatment and reliance should not be placed on it. For personalised medical or nutrition advice, please make an appointment with your doctor, dietitian or qualified health careprofessional.