Updated: Jun 18, 2021
When you ask people today what diets they are trying or what they hear other people talk about, mainly two come up; intermittent fasting and keto (ketogenic diet).
I thought we should look more into the ketogenic diet, how it came about, what it is, and if it is good for long term health.
The ketogenic diet came about in order to treat a specific condition; epilepsy. More specifically it has been used mainly for children with epilepsy and started as early as in the 1920’s. Back then the composition of the diet looked like this:
Protein: 1 gram per kilo body weight Carbohydrates: 10-15 gram per day Fat: The remainder of calories needed
The results in the children with epilepsy were fairly good, but the diet was used less and less as medications treating epilepsy entered the market. Today it is sometimes used in children who see no improvement from medications. The exact mechanism behind why ketogenic diet has an impact on epilepsy is still mostly unknown.
One study has shown growth-delay in children using a ketogenic diet but it is not enough to draw a true conclusion at this point. More studies would be needed.
The first study to look at long term effects in children who were using the diet but no longer are, showed no specific health issues. The cholesterol values were back to normal, compared to being abnormal during the use of the ketogenic diet.
Today however, many people are using the ketogenic diet for a number of different reasons. Some for weight loss, some state that they feel “more energized” or “feel better” and so on.
The name ketogenic diet comes from ketones. As the diet is very low in carbohydrates the body is forced to go after other sources for fuel for energy. It starts to break down fat and in this catabolic (break down) process the liver produces ketones for energy. You end up in a state of ketosis. This can be measured in your blood and urine. This is the body’s backup plan for when it does not get enough carbohydrates.
If you have diabetes, the buildup of ketones can make your blood acidic and your blood glucose level extremely high. This is called DKA (diabetic ketoacidosis). This is a life threatening situation and happens because your body does not produce enough insulin. If you have diabetes and want to try a ketogenic diet it is important that you speak with your doctor first.
So what about using a ketogenic diet for “health and weight loss?” What do we know about the effect on our heart and brain health (cardiovascular health)?
The first problem we run into is that people have very different ideas about what a ketogenic diet is. Many people may think that they are eating “keto” but despite their low carbohydrate diet, the carb intake is too high to actually induce the ketone production.
The second problem is what your high fat intake looks like. Just as with carbohydrates and protein, there are different qualities and characteristics of fat. Some have better nutritional quality than others. This is why we can never conclude that “all carbs are bad” or “all fats are bad”. Choosing fatty foods which mainly consists of unsaturated fats is vital on a ketogenic diet.
Another problem is missing out on vital nutrients from carbohydrates as only about 5% of your daily calories would come from carbohydrates. Fiber is one of the nutrients that has in several studies shown to help with increased satiety (feeling of fullness), cholesterol and digestive health. Fiber is found in carbohydrates and the recommended intake is 25-30 gram per day.
With this low level of carbohydrates there is also a risk of not getting enough vitamins, minerals, and phytonutrients.
There are not enough long term studies made on adults using a ketogenic diet intermittently or long term to make safe conclusions. However, there are studies made on yo-yo dieting (losing and gaining weight repeatedly) and also having high fluctuating cholesterol levels, systolic blood pressure, BMI, and blood glucose who show an increased risk of mortality and cardiovascular diseases.
There are no specific foods that can put you in a ketogenic state. It is all about your diet composition and if you consume so few carbohydrates that you force your body into producing ketones. There is a lot of research going on about ketogenic diet and ketones as fuel so hopefully we will have more clarity in the future. However, nutrition research is extremely complicated for ethical reasons and human behavior. We simply cannot lock thousands of people in and control everything they eat and do. This is why you mostly see correlation as a result of a human nutrition study and not actual causation.
If you are considering using a ketogenic diet as a way of losing weight you will probably succeed in the short term. However, any diet, or more preferable eating pattern, that cannot be sustained for the rest of your life, is not the best choice in my own opinion as a dietitian.
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