The keto diet

Good morning.

The ketogenic is a high-fat, low-carbohydrate, and low-moderate protein diet.

The idea behind this dietary approach is the low carbohydrate intake allows the body to burn more fat, including body fat, as a fuel source.

Glucose - the end product of carbohydrate breakdown - is the primary energy source for the brain, as it can travel in the blood and cross the blood-brain barrier to be used as fuel (fatty acids and amino acids cannot be used by the brain).

When carbohydrate intake is restricted, stores diminish and blood glucose eventually drops. This is problematic, because your brain requires fuel.

Enter ketones.

Ketones are synthesised from fatty acids, in the liver. 

Ketones enter the bloodstream and can also cross the blood-brain barrier, to be used for fuel in the brain.

Fat is now the predominant energy source for the body, with ketones taking on the role of glucose for the brain’s fuel supply.

Whilst a huge amount of fat is being burnt for energy on a ketogenic diet, it’s important to remember that fat is also the predominant energy source through the intake.

So unless energy intake decreases, or energy expenditure increases, the energy balance that was present before the ketogenic diet will likely be maintained. 

This means that if you weren’t losing weight before, you won’t be now, besides 1-2 kg water loss during the first week (from clearing carbohydrate stores).

The big question with the ketogenic diet is: “how necessary is this for weight loss?”

The answer: not very.

Tom Fitzgerald