What is a keto diet?
The ketogenic diet is a very low carbohydrate diet and a very high fat diet. The mechanisms behind it are as follows: when you heavily restrict carbohydrate intake your body switches from burning glucose to fat stores.
It is vital to remember your body’s preferred source of energy/fuel is glucose and when glucose is not available your body uses stored glucose (glycogen). Glycogen stores are limited and so once your body has used all the glucose and glycogen your body shifts towards using fat reserves and sometimes protein from your muscles.
Your brain heavily relies on glucose as a fuel so this diet can have a profound effect on cognitive functions I.e., brain fog.
Where did the idea come from?
It was developed in the 1920’s as a treatment for children with epilepsy that would not respond to drugs. Even now 100 years later, doctors don’t really understand exactly why this diet reduces seizures, but we do know that it works rather effectively.
When people are on this diet though, it is imperative they embark upon it under the supervision of their GP and dietitian because it was be quite dangerous if not done correctly.
Is it a healthy diet?
A lot of foods which you must avoid on this diet are foods that are high in fibre (rice, potatoes, bread, quinoa, starchy veg etc.) The Government, NHS and public health guidelines all recommend everyone should be aiming for at least 30g fibre a day (15g per 1000cals).
One of the dangers of this diet is that you end up not getting sufficient fibre meaning constipation is a common side effect as the rate of digestion is slowed down.
Carbohydrates attract a lot of water and when broken down, it is referred to/ known as a ‘bulky’ molecule. Hence why people feel ‘leaner’ when they reduce/cut back on carbs as the initial weight loss experienced is just water weight as the glucose and glycogen is used up along with the water molecules that are attached to them.
The sudden decrease in weight is water weight & not actual fat loss.
You are likely to feel lighter for 2 reasons, you’re restricting both calories and a food group. It is hard to eat a high fat diet because you are likely to feel quite sick from the high proportion of higher fat foods which tend to be quite rich.
The initial drop in water and consequently feeling ‘lighter’ may serve as positive reinforcement of dietary behaviour but it is short lived, will plateau and lead to possible frustration and further restriction which will be difficult to keep up with- inevitably leading to ‘falling off the bandwagon’, blaming oneself for a ‘lack of control’ and this facilitates unhealthy, unhelpful and quite frankly dangerous thoughts and behaviours around food.
Is there are evidence/research into it?
There is NO research whatsoever for the keto diet supporting any aspect of public health. There is no data suggesting this way of eating is beneficial for humans. The diet is high in animal proteins/ products including red meats, which we know is not sustainable and there is a myriad of evidence showing we need to be reducing animal consumption and animal products, whilst simultaneously increasing plant- based foods.
Interestingly, when high fat/low carb diets are compared to low fat/high carb diets: the weight loss seen across the 2 groups is very similar and perhaps more importantly the weight loss does seem to creep back regardless of the diet.
Food for thought:
Ultimately, when you micromanage your calorie intake, restrict things heavily, track macronutrients and calories constantly, it disconnects you from your body’s own internal primitive cues i.e., hunger, satiety, and cravings because you are not listening to your body.
Instead, you are relying on extrinsic factors (numbers and rules) in order to help you determine what you can and cannot eat - not a recipe for a healthy, sustainable diet.