All things keto
The ketogenic diet initially came around, as it was used to treat epilepsy. However, nowadays it seems like it’s the most popular diet, mostly for weight loss purposes.
Keto is characterised by consuming a very low amount of carbs (5-10% of total energy intake). It can be as little as 20 g/d, which can very quickly add up just from green, non-starchy vegetables. For example, half a cabbage, one medium sweet potato, 2 leeks, one cauliflower head or a few handfuls of berries each amount to ~20 g of carbs.
The type of fat also matters in the keto lifestyle, as poly- and mono-unsaturated fats are preferred over saturated. The same is advised by the national eat well guidelines, except that in keto, the calories you don’t consume as carbs, are consumed as unsaturated fats and proteins, resulting in an overall high fat intake (~60% of total energy intake).
The typical sources of fat in keto include nuts, seeds, avocado, oily fish and various oils, while the carbs are obtained from non-starchy vegetables and berries.
The carbs that are included, come from complex carbs (the type of carbs that release glucose slowly into the bloodstream, instead of giving you a blood sugar spike and dip as do simple carbs).
Carbs (glucose) are the primary source of energy, while the point of keto is to put you in a ketogenic state (ketosis), where ketones, which form in the liver from the breakdown of fats, become the main source of energy when glucose is running low. This essentially means that you burn fat for fuel. Sounds amazing, doesn’t it?!
It may very well be in some cases. For example, keto may be beneficial for someone with diabetes or for someone who is not necessarily diabetic, but who does not respond well to insulin and therefore has high blood sugar. For diabetic patients, a keto diet may reduce the inconvenience of carb counting and help balance blood glucose, but it must be overlooked by a clinician.
Do not try this without consulting your doctor, due to the risk of ketoacidosis. It is a condition where the blood pH changes by becoming too acidic, which if not managed in time may lead to death.
Ketoacidosis may also occur in non-diabetic individuals, who have an over-active thyroid, abuse alcohol or engage in prolonged fasting. This means you might need to be careful if you do keto and extensive intermittent fasting.
If you think you can eat alkaline foods to prevent this from happening by “alkalising your blood” - not food can change the pH of our blood and thanks to evolution it can’t because it would be life-threatening. Humans die if the blood pH is outside of the pH range of 7.35-7.45.
Keto may be beneficial when managing PCOS. This is because PCOS can be characterised by high insulin, which encourages the ovaries to produce more androgens, such as testosterone. High androgens may interfere with ovulation and therefore, fertility. So, managing carb intake may help manage insulin and therefore, hormones.
In terms of weight loss, keto may result in short-term weight loss due to a potential calorie deficit due to reduced carbs, but just like with any other diet, the weight comes back on when you’re no longer on the diet and eating a large variety of foods.
One of the main drawbacks of keto is reduced fibre intake. Fibre is linked with increased variety and size of gut microbiota populations, which in turn results in a healthy gut and positive overall health outcomes, such as reduced risk of multiple metabolic conditions. In the UK, the current average fibre intake is ~18 g/d, when the recommended intake is 30 g/d. A keto diet may further reduce your fibre intake, as it is obtained from different fruit, vegetables and other plant foods, which do not qualify to the “ok” list for keto in terms of their carb content.
Take-away:
1. If you have a legitimate reason why keto may work for you - great, just bear in mind that long-term studies are lacking, which means that the potential risks of being in ketosis for an extensive period of time are not crystal clear.
2. Be mindful of your fibre intake, which largely impacts your gut and overall health.
3. Keep in mind that a low variety of fruit and vegetables may limit your vitamin and mineral intake.
