What the f*** is Keto? (& Should YOU try it?)
Every so often a magic new diet appears, designed to promise the weight loss you’ve been craving.
One of the most popular diets for the last 20 years is the ketogenic diet.
It’s been backed by lots of celebrities and influencers, claiming that the weight loss benefits are just too good to pass on.
So should you try the keto diet? Is it dangerous? Will it help you lose weight? What foods can you actually eat?
We’ll delve into all this as well as explaining the science behind the diet, the benefits and the disadvantages. Let's go.
What is a keto diet?
Keto is short for ketogenic and it’s a diet that causes your body to generate ketones.
Bear with me.
The body’s primary food source is glucose, which your body gets from carbohydrates - also known as carbs.
Carbs are found in foods like bread, rice, pasta, fruits, and vegetables. When we eat carbs, they get broken down into glucose during digestion. And glucose is a type of sugar that serves as the body's preferred source of energy.
It can be readily absorbed into the bloodstream and transported to cells throughout the body to be used for various functions, including fuelling muscles and providing brain power.
When we eat carbs, our pancreas releases a hormone called insulin in response.
Insulin's role is to help transport glucose from the bloodstream into cells, where it can be used for energy.
Excess glucose that isn't immediately needed for energy is stored in the liver and muscles as a molecule called glycogen. This glycogen can be broken down into glucose later when needed.
So, our body's tissues primarily rely on carbs to produce energy. But, when we cut our daily carb intake to under 50 grams, something interesting happens.
Insulin production drops significantly, pushing the body into a different metabolic state. This shift leads to a depletion of glycogen stores in your liver and muscles and sets off a series of metabolic transformations.
In this scenario, two key metabolic processes become prominent: gluconeogenesis and ketogenesis.
Gluconeogenesis is the body's way of creating its own glucose internally, primarily in the liver.
It does this using various building blocks like pyruvate, lactic acid, glycerol, and specific amino acids.
When there's a shortage of glucose, and the body's usual glucose sources can't meet its energy needs in the form of ATP, a metabolic shift occurs.
This shift leads to ketogenesis, which introduces ketone bodies as an alternative energy source, taking over from glucose as the body's primary fuel source.
During ketogenesis, insulin secretion is low because of feedback from blood glucose levels, and this leads to a reduction in the signals that promote fat and glucose storage in the body
Also, other hormonal changes contribute to the increased breakdown of fats, resulting in the formation of fatty acids.
These fatty acids are then converted into primary ketone bodies, such as acetoacetate and acetone.
These ketone bodies accumulate in the body as long as the ketogenic diet is maintained, providing an alternative energy source.
This metabolic state is commonly known as 'nutritional ketosis.' Nutritional ketosis is generally considered safe, as it involves the production of ketone bodies in moderate amounts without significantly affecting blood pH levels.
It's important to note that nutritional ketosis is distinct from ketoacidosis, a severe and life-threatening condition characterised by excessively high levels of ketone bodies, which can lead to blood acidosis.
I’ve spoken about this in a previous video where I encountered this emergency in a hopsital for the first time.
Ok - TLDR:
Ketosis occurs when the body experiences a significant reduction in carbohydrate intake, causing blood glucose levels to drop.
When there isn't enough glucose available to meet the body's energy demands, the body needs an alternative source of fuel. This is where ketosis comes into play.
In the absence of glucose, the liver begins to break down stored fats into molecules called fatty acids and ketone bodies.
Ketone bodies can be used by most cells in the body as an energy source, including the brain.
There are also different versions of keto diets but I won’t go into detail about them here.
How do I get into ketosis?
You drop your carbs drastically.
The majority ketogenic diets recommend having no more than 20 to 50 grams of carbs per day. But this figure depends on your calorie goal too.
The figure that is thrown around in the keto space is to consume no more than 5% of your total calories from carbs.
Let me put that into perspective.
The typical Western diet often consists of 300-400 grams of carbohydrates per day or even more.
By having a banana or a couple of slices of toast, you’ve pretty much maxed out your allowance of carbs when you’re on a keto diet. It comes to no surprise then that educing carb levels means cutting out rice, bread, pasta and pizza.
Achieving such low levels of carbs also means skipping legumes, root vegetables, most fruits and starchy veg like potatoes.
So if you can’t eat carbs then what foods can you eat?
Foods that are generally allowed include fatty meats, fish, eggs, oils, nuts, cheese, and low-carb vegetables like leafy greens.
So why would anyone want to follow a keto diet?
The main reason is fat loss.
When you start a ketogenic diet, one of the first noticeable effects is often rapid weight loss. Much of this initial weight loss is attributed to the depletion of glycogen stores in the body.
Glycogen is a form of stored carbohydrate in the liver and muscles. It's stored along with water molecules.
For every gram of glycogen stored, the body retains about 4 grams of water.
On a standard high-carbohydrate diet, your glycogen stores are continually replenished as you consume carbohydrates.
However, when you switch to a low-carb, ketogenic diet, your carbohydrate intake drops dramatically. As a result, your body starts utilising stored glycogen for energy. When glycogen is broken down and used, the water molecules bound to it are released.
This leads to an initial loss of water weight, which can be quite significant - Some people may shed a couple of kilos of water weight within the first few days of starting a keto diet.
While this initial drop in weight is mainly due to water loss, it can be motivating and encouraging for those looking to kickstart their weight loss journey.
It's important to note that this water weight loss is temporary and not indicative of long-term fat loss.
As glycogen stores become depleted, the body will transition to using fat stores for energy, which is when true fat loss begins.
So how do people lose weight on keto diets?
It’s quite simple. It’s because of a reduction in calorie intake.
When people start a keto diet, they often naturally consume fewer calories than they would on a high-carb diet.
The diet is quite restrictive.
You can’t eat a lot of foods that are seen in western diets. Also carbs are calorie-dense macronutrients, providing about 4 calories per gram. On a ketogenic diet, carbohydrate intake is significantly reduced, which inherently lowers calorie consumption.
The benefits of following a keto diet:
It can help with appetite control.
High-fat and protein-rich foods tend to be more filling than high-carb foods.
As a result, a reduced appetite means that you're less likely to overeat or consume excessive calories, which can contribute to weight loss. Being in ketosis has also been shown to reduce appetite and cravings for high calorie and high carb meals.
Effect on diabetes.
In a recent randomised, crossover trial, they compared the impacts of ketogenic and Mediterranean diets on blood glucose control in 33 adults with pre-diabetes or type 2 diabetes.
It's called a crossover trial because the participants followed one of the 2 diets for 12 weeks, and then switched and changed to the other diet for another 12 weeks.
They used continuous glucose monitoring and 24 hour dietary recalls which incorporated a structured interview to determine what food and drink they ate.
So what did they find?
- Both diets resulted in weight loss.
- Both diets had a reduction in HbA1c levels.
HbA1c is known as glycated haemoglobin - It’s a test that measures the amount of glucose attached to your red blood cells.
And it provides a snapshot of how well your blood sugar levels are being controlled for last 90 days or so, because that is the typical lifespan of a blood cell.
If you have diabetes, the ideal level is 6.5%, or 48 mmol/mol or below.
The issues with ketogenic diets.
While it can be effective for some individuals in achieving weight loss and other health goals, it comes with a few potential risks..
1. Keto flu
Many people experience short-term adverse effects when starting a keto diet, known as the "keto flu."
Symptoms like nausea, vomiting, headache, fatigue, reduced exercise tolerance, and constipation can be uncomfortable but usually improve within a few days to week.
2. Nutrient deficiencies
Keto diets are highly restrictive and can lead to inadequate intake of essential vitamins and minerals.
This lack of variety in food choices can increase the risk of nutrient deficiencies over time.
3. Digestive issues
High-fat, low-fibre diets, which are typical of the ketogenic diet, can cause digestive problems such as constipation, diarrhoea, and bloating.
The limited fibre intake can negatively affect gut health which is not good news.
4. Kidney stone risk
The diet's high-fat and low-carbohydrate nature can increase the risk of developing kidney stones. This is partly because ketosis can change urine composition, potentially leading to stone formation.
5. Exercise performance
Keto diets severely restrict carb intake, which is the primary source of energy during high-intensity exercise.
With limited carbs, your glycogen stores, which provide readily available energy to your muscles, become depleted. This can lead to decreased energy levels and fatigue especially during intense workouts.
6. Protein interference
If you’re like me and have a relatively high protein intake of 2 grams per kilo of body weight, then this diet might not suit you.
This is because eating too much protein can interfere with ketosis.
When you eat too much protein, your body converts the excess amino acids into glucose through gluconeogenesis, which we discussed earlier.
This can lead to an increase in blood glucose levels, potentially pulling you out of ketosis.
7. Sustainability
Many people find it challenging to maintain a ketogenic diet over the long term due to its restrictive nature, which can lead to diet fatigue and increased risk of regaining lost weight.
It means you have to stay away from foods like bread, rice, pasta, fruit, pizza etc. (All the good shit).
8. Heart disease risk
Keto diets are often high in saturated fats, which can raise concerns about heart health.
High intake of saturated fats from butter and processed meats increase the risk of heart disease, especially when it's not balanced with healthy fats and fibre.
A meta-analysis of 68 randomised controlled trials that involved ketogenic diets found a clinically meaningful increase in LDL-C in people that followed keto diets.
LDL-C stands for "low-density lipoprotein cholesterol," and it's a type of cholesterol in your blood.
Think of it as a "cholesterol carrier" that carries cholesterol from your liver to other parts of your body where it's needed.
While cholesterol is necessary for various functions, having too much of this carrier can sometimes be a big concern for your health.
LDL-C is the main driver of atherosclerosis.
And this can lead to heart attacks.
Having said this, you can make your keto diet healthier with mindful choices.
The key aspect to consider is swapping the saturated fats with healthier unsaturated fats. Eating fatty fish, avocados, salad vegetables, nuts and seeds and using olive oil is a good place to start.
And don’t forget about fibre.
Should you try a keto diet?
While it can be effective for specific purposes, it's not a one-size-fits-all solution. Some people love keto and others just love carbs too much.
It depends on your health goals and whether you can adhere to the diet in the long term. Because if you can’t stick to it, then there really isn’t much point in starting.
And remember, if weight loss is what you’re looking for, then keto diets will not magically help you lose weight.
It is all about the calories.
A quote from a great
Have a sweet day,
Z
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