June 15, 2018
Ketosis is a metabolic state in which fat is metabolised to produce ketone bodies which provide energy rather than glucose.
Our bodies preferred fuel source is glucose which is largely consumed in the diet in the form of carbohydrates which are found in breads, cereals, grains, legumes, fruit, starchy vegetables and dairy products and sugar.
Once we take carbs out of the diet, your body has to look elsewhere for fuel so it will break down fat – either dietary fat or stored body fat – to produce ketone bodies or ketones for fuel.
The first few days of following a ketogenic diet are not much fun as your body is still looking for carbohydrates to burn. You may be hungry, low in energy, a bit irritable, more likely to get sick and you might not be able to train at your peak.
Once you’re in ketosis, your appetite is reduced for a number of reasons. A high protein intake has a higher satiety effect; we see changes in levels of appetite control hormones and the ketone bodies themselves have a direct appetite suppressant action.
One of the by-products of the breakdown of ketones is acetone. Acetone is the chemical responsible for the production of nail polish remover and some paint thinners. Acetone is exhaled through the lungs, thus making your breath smell a little like nail polish remover. Aside from the need to use breath mints, this is not harmful and is a sure-fire sign that your body is in ketosis.
It can be hard to consume enough fibre on a ketogenic diet as many high-fibre foods are excluded e.g. grains, cereals, too much fruit, legumes, so a common complaint from followers is they can get bound up. It is possible to consume enough fibre from non-starchy vegies or you may need to take a fibre supplement to keep your bowels moving.
Although it seems counter-intuitive to be eating more fat and losing weight, now that your body is burning body fat as its main fuel source, you can lose weight very quickly. In addition, your appetite is suppressed so you’re less likely to overeat or go back for seconds.
On a ketogenic diet, you’ll limit the spikes in blood sugars that come with frequent carbohydrate and sugar intake. As a result, your body doesn’t need to produce as much insulin. Low insulin levels mean that your body is better able to break down fat to be used as fuel.
Once your body is in ketosis, your energy levels should come back to normal or even better! Now that you are using fat as fuel, you are not short of an energy supply and no longer relying on your dietary intake as your main source of energy.