Are all calories the same?

We have been told many times, that a calorie is a calorie. We've been told that on a macronutrient scale, it doesn't really matter where a calorie is coming from. We've also been told that eating too much calories will make us fat, while eating too few calories will make us loose weight.

I decided to write this post because I believe that what we've been told is not entirely correct. Yes, it is intuitive and it kind of fits the basic principles of physics. It is also very easy to understand. But is it the truth?

Recently, I found some information that made me thinking. On this blog, I've already been writing about Sam Feltham, who went through three 21-days long dietary experiments (or as he calls them: challenges). So think about this: same guy, same amount of calories, same period of time, same lifestyle. The only difference was his diet.

So what Sam did was the following. First experiment, he did a cca. 5.800kcal per day LCHF diet. Since he ate much more calories than he required, we would expect that he gained weight. Second, he did a cca. 5.800kcal per day high carb junk food diet. Again, we would expect him to gain even more weight, roundabout the same as on the first experiment, due to the fact that he ate the same amount of calories. And finally, he went to another LCHF diet where he ate exactly his daily caloric requirement. Under the assumptions that what we've all been told is true, we would expect him to maintain the weight that he gained during the previous two fattening experiments.

Below table shows that really happened. Sam tracked his weight and his waistline throughout all experiments.

Sam Feltham's 21-day dietary challenges	LCHF diet (to gain weight)	High carb diet (to gain weight)	LCHF diet (to maintain weight)
Daily caloric intake	cca. 5.800 kcal	cca. 5.800 kcal	cca. 3.600 kcal
Starting weight	85,6 kg	89,7 kg	96,0 kg
Ending weight	86,9 kg	96,8 kg	90,35kg
Difference	+1,3 kg	+7,1 kg	-5,65kg
Starting waistline	79,5 cm	79,5 cm	88,25 cm
Ending waistline	76,5 cm	88,75 cm	80,75cm
Difference	-3 cm	+9,25 cm	-7,5cm

Do you see something strange?

Sam Feltham during his third experiment, where
it would be expected he maintained his weight. But
in fact, he lost plenty of it.

On the first experiment, one would expect Sam to gain a significant amount of weight and waistline. But he only gained a little bit of weight and even lost a bit of his waistline. Then, on the second experiment, with the same amount of calories but on a different diet, Sam gained weight just as expected. And also quite a bit of waistline. Finally, on the third experiment, Sam should maintain his weight, but he didn't. He lost quite a bit of eat (almost as much as he gained on the second experiment) and he also lost plenty of waistline.

To me, Sam's data suggest that what we've been told is not entirely correct. It is obvious that effects of calories on his weight and waistline changed a lot when he switched between low carb-high fat and high carb-low fat diet.

You may say that uncontrolled N=1 experiments don't mean much, and you would be correct: they don't mean much! But what they do mean is that we should at least ask how can this be. So, is Sam Feltham just an exception to the rule that a calorie is a calorie, or is there something that we weren't told?

The first law of thermodynamics

Statement that a calorie is a calorie is in line with the first law of thermodynamics. This law is one of the most fundamental natural laws. It is so fundamental that in Slovenia and in many other countries, we teach children in primary school about it. It speaks about conservation of energy and it says that energy can not be created, nor can be destroyed. It can only be converted from one form to another, but total amount of energy is always the same. The first law of thermodynamics is universally correct, apart from nuclear physics, where it is replaced by another law - but since this is a blog about nutrition, not physics, I won't go into it any further. Especially because our bodies are not capable of nuclear reactions.

Another thing some people often forget is what exactly is a calorie. A calorie is a physical unit which represents amount of energy. Just like a meter is a measurement unit for length, so is a calore a measurement unit for energy.

The first law of thermodynamics in nutrition means that if Sam Feltham eats 5.800 calories of energy, this energy has to go somewhere. Sam didn't create any additional energy (nor any additional calories) and he also didn't destroy any. If Sam eats 5.800 calories, his body now contains 5,800 calories, no matter what kind of diet he is on. Since Sam's body obeys the first law of thermodynamics, we can ask: where did the energy (or "the calories") go in the first and where in the second experiment?

Where do calories go?

There are several different models which help us to analyze distribution of energy around different processes. I decided to use Dr. Peter Attia's model, because it is easy to understand and very intuitive.

Dr. Attia says that there are 4 major things for which we use energy, and this means that there are 4 major places where calories go:

Dr. Peter Attia before and during his LCHF lifestyle. Love
the second T shirt!

• digestion
• activities of daily living
• exercise
• resting metabolic rate

To Dr. Attia's model, I would like to add that some of the calories can also be stored (or retrieved from) the adipose tissue (aka "fat cells"), and some may be left in our poo. Our digestive system is extremely efficient and for this reason, we can neglect the calories that we flush down the toilet. On the other hand, the calories stored in our adipose tissue is the difference between the food we eat and the total sum of calories in the above four categories.

What does it mean for Sam and his first two experiments? Both times, he ate the same amount of calories, but the second time, he stored much more energy in the adipose tissue as the first time. This means that the total sum of caloric expenditure in the first experiment was larger than in the second one. So, let's analyse the categories to see where exactly could the differences take place.

Digestion. Digesting the food we eat requires some energy. There are plenty of muscles involved in digestion and there are complex chemical reactions going on which require heat. But overall, comparing to the amount of energy we eat, digestion uses only a small part of it. Of course, some foods take more than the others to digest and surely, there was some variety in Sam's usage of calories for digestion on different diets. But in the big picture, the differences are so small that they can be neglected. This is also logic from the evolutionary standpoint. If our digestion was very inefficient, we probably wouldn't exist in this world, since even in abundance of food we would end up with only a small portion of energy after digestion would have taken its toll.
Bottom line: changing your diet has very little effect on your energy requirements to digest food.

Activities of daily living. This is energy required to carry us around the world. It allows us to work and to think. Certainly, between people, there are big differences of how much energy the spend on activities of daily living. An office worker will burn much less than construction worker. The amount of energy depends on our lifestyle, habits and obligations. Theoretically, we could significantly influence the caloric requirements of activities of daily living by changing our lifestyle (and our job), but in reality, very few people do it. I mean, think about it: would you change your job to become a construction worker or a miner just to increase the caloric requirements in this category? I would assume that your answer is "no" and because of that, we may assume that energy expenditure on activities of daily living of an individual is pretty much constant. Furthermore, Sam Feltham deliberately followed his regular daily habits quite strictly, in order to keep the energy requirements constant.
Bottom line: changing the diet has no effect on energy expenditure on activities of daily living.

No doubt, a great poster. Too bad it's
a fairy tale. When it comes to being
lean, mind, heart and might don't
have much to do with it!

Exercise. This is by far the most popular category for controlling daily consumption. Again, this varies weekly caloric expenditure by about 2.000 calories. If this person was male, that would be roundabout 13% of his weekly caloric requirements. It is something, but not nearly as much as most people believe. And remember - the 13% difference is only if you went from a couch potato to a fitness fanatic. Every time you would skip a training session, this value would go down for a quarter. Anyway, back to Sam Feltham, who has been a very active person before and during his experiments, so his exercise expenditure in this category didn't change.
from person to person. We often hear something like: "Are you fat? Well, do more exercise!" So, let's take a look at the numbers. We could roughly estimate that a person can burn about 500 calories in a two-hour exercise. As you may know, it is not recommended (nor very practical) to exercise more frequently than 4 times per week. So I would say that someone who went from a total couch potato with no exercise to a full on fitness fanatic can increase his
Bottom line: it is possible to burn more calories with exercise, but in total energy expenditure, the amount is relatively small. Much smaller than most people would expect. It is also very sensitive to human error (i.e. skipping training sessions).

Resting metabolic rate. In the three caloric categories analysed so far, nothing has changed for Sam. So let's take a look at this last one. It is an important one too, since resting metabolic rate is the amount of calories we need for our body to function properly. We use it to breathe, to fuel our heart and internal organs, to think, to maintain our body temperature etc. It is the only of the four categories where we burn energy non-stop, 24 hours per day. Furthermore, resting metabolic rate takes plenty of calories, comparing to the other three categories. Dr. Peter Attia made and experiment on himself, when he switched from western to LCHF diet. He noticed that his resting metabolic rate more than doubled! This means that after he changed to LCHF, he burned more calories while sleeping, thinking, to pump his heart and to fuel all those important biochemical reactions in his body. Sam Feltham didn't measure his resting metabolic rate, but since he didn't change anything in the other three categories, we have a good reason to believe that there was a change in this category.
Bottom line: according to Dr. Peter Attia's measurements and Sam Feltham's experience, nutrition has a significant effect on resting metabolic rate. And since resting metabolic rate takes a big part of our caloric consumption, the effect of nutrition on our total caloric consumption is significant.

So, what happened to Sam Feltham? Let's summarize:

• no considerable changes in energy required for digestion;
• no changes in daily activities;
• no changes in exercise;
• LCHF diet seems to raise resting metabolic rate in comparison to a high carb diet;

Human body is not an internal combustion engine!

For an internal combustion engine, a calorie is a calorie. Think of your car. If you fill up your tank and go for a long lazy drive, you will do more miles. It wouldn't burn plenty of fuel (calories) per mile and hence do more. But if you would go for a sporty drive with lot's of accelerations and high revving, you would do less miles with the same amount of fuel.

If you would believe that your body and a combustion engine are based on a similar concept, you would say that all you need to do to loose weight is to put less fuel in your tank and drive around like crazy. Specifically: eat less - exercise more. But our body is not a combustion engine and even if it was, this would be a bad advice.

1. You would be hungry all the time, and that would have a bad impact on the quality of your life.
2. You would neglect three categories that a body has, but car doesn't (digestion, regular daily activities and resting metabolic rate).
3. You wouldn't change resting metabolic rate, unlike for a car, takes up the majority of calories. And, seems to be affected by the kind of food we eat.

The difference between calories

Sam Feltham's experiments are consistent in terms that in all three cases, he changed his diet, but not his lifestyle. Because of that, three categories of energy expenditures didn't change. The only thing that changed was resting metabolic rate, which seems to be considerably higher at high fat diets, comparing to low fat diets. This is the reason why high fat diets are very effective and do not require any exercise. Please note that I am not saying that you shouldn't exercise. Exercise brings many benefits, but weight loss isn't one of them (I borrowed this quote from Dr. Peter Attia).

I believe it is way easier and also much more effective to increase resting metabolic rate by eating a high fat diet, than working hard to exercise out the excess calories, while eating small portions. But if you choose a more popular diet that is very restrictive on saturated fats and more permissive on proteins and carbs (even if it permits low GI carbs only), cutting down calories and exercise will be your only options.

As a reward for going through another of my extensively long posts, I found an interesting video on Youtube, which illustrates how calories are measured. You will see the difference between toasted oats (high carb) and cheese puffs (high fat). You will see that cheese puffs have way more calories. Without Sam Feltham's experiments, one would easily draw a conclusion, that toasted oats are better. But remember: your body is NOT a combustion engine!

References

It wouldn't be possible to write this post without information generously provided by Sam Feltham, Peter Attia and Andreas Eenfeldt. They all have great websites with plenty of useful and down to earth information and if you have further interest in the subject, I recommend you to check them out.

My LCHF lifestyle - week 6

Week 6 is over and here is an update of my progress. You may remember that last week I came to a plateau and that my suspicions were aimed towards me not eating enough fat. For this reason, I was extra careful this week and managed to get 80% of all calories from fat. Presumably, this resulted in ketosis and as a result, my progress is back on a fast track.

My weight and waistline progress in the past 6 weeks.
I was strict on ketogenic diet and it shows in increased
rate of progress.

Weight

Today (Oct 28th 2013):	106,0kg
7 days ago (Oct 21th 2013):	107,8kg
LCHF Day 1 (Sep 20th 2013):	112,0kg
Weekly progress:	-1,8kg
Absolute progress:	-6,0kg

As you can see, I lost 6 kilograms altogether and 1,8 kilograms since last Monday. This means that my progress is similar to the one I had in the first two weeks. I'm very happy for that!

Waistline

Today (Oct 28th 2013):	118,5kg
7 days ago (Oct 21th 2013):	119,5kg
LCHF Day 1 (Sep 20th 2013):	126,0kg
Weekly progress:	-1,0cm
Absolute progress:	-7,5cm

For the third week in a row, my waistline is keeping going down at a steady pace of 1cm per week. Fantastic!!!

My blood markers

It has been a month since I started testing my blood for glucose, triglycerides and cholesterol.

	Last month	Today	Change
Glucose (mg/dl)	85 - 95	82 - 88	lower levels
Cholesterol	284	234	-50
Triglycerides	not measured	149	/

As you can see, a month ago I had normal glucose, very high cholesterol and unknown triglycerides. Today, glucose levels are even lower and kept rather constant throughout the day. My triglycerides are just at the top of the recommended limit, which is 150mg/dl. My cholesterol dropped from 284mg/dl to 234mg/dl, which means it went from "high" to "elevated". I am aiming for below 200mg/dl, which is recommended.

The food that is apparently making my blood vessels
and my heart very happy. My typical shopping cart.

I fell very confident to say that replacing carbohydrates with fat is very beneficial for my cholesterol and triglycerides. Two our of three markers are in the safe zone, while the third one is approaching it very quickly. Unfortunately, I can't find any data to compare my drop of cholesterol. It would be interesting to see monthly changes of cholesterol of people who went on different kinds of diets. Also, I am planning to visit my doctor for a more detailed analysis, namely LDL and HDL levels. I am certain that the levels are OK or at least very nearly there, but I feel responsibility to really check it out.

Plans for week 7

Following the 80-20-150 rule in week 6 turned out fantastic results and I will definitively keep it going. I am feeling fantastic, without hunger and cravings. I don't miss bread, potatoes, rice, pasta and other food rich in carbohydrates, and at the same time, I am loving my eggs, bacon, cream, mayo, fish, home made almond butter.

That's it for this week's report. If you like this blog, please share it on Facebook and/or Twitter and spread the word to everyone struggling with obesity, cholesterol and whatnot. It is really easy, just click the social network icon below. Also, if you would like to comment on what I am saying or suggest a diet-related topic you are interested in, feel free to put in in the comments below.

I wish you a nice, successful and healthy week!

My LCHF lifestyle - week 5

Week 5 is over and here is my new progress update. I decided to make this update a bit more standardized, so that you will be able to follow my progress easier.

My progress so far. Waistline is going down steadily,
but my weight is starting to plateau. Read this post
to see why I think this is happening.

Weight

Today (Oct 21th 2013):	107,8kg
7 days ago (Oct 14th 2013):	107,4kg
LCHF Day 1 (Sep 20th 2013):	112,0kg
Weekly progress:	+0,4kg
Absolute progress:	-4,2kg

As you can see, I am a bit over 4 kilograms down, but comparing to last week, I am 0,4kg up. Furthermore, I am 0,2kg up comparing to two weeks ago. So obviously, I am back to gaining weight. But before jumping to any conclusions, let's take a look at waistline measurements.

Waistline

Today (Oct 21th 2013):	119,5kg
7 days ago (Oct 14th 2013):	120,5kg
LCHF Day 1 (Sep 20th 2013):	126,0kg
Weekly progress:	-1,0cm
Absolute progress:	-6,5cm

I am happy to notice that my waistline is steadily going down. Since the past few weeks, I am noticing a steady weekly reduction for 1cm per week. I am very happy about that, although I do not understand completely how come my waistline and also other parts of my body are reducing, but my weight is slightly increasing. I have an idea though...

Was I really eating LCHF?

Since my weight started to plateau, I became very curious what could be the reason for that. So, last week, I took out my trusty glucose meter and started poking more regularly myself to measure blood sugar. I noticed that on average, my blood sugar was higher than it used to be on the second week of LCHF. It was still low. On average a bit over 85mg/dl and never over 95mg/dl at any time of day, which is withing normal fasting blood sugar limits, but not as low as it used to be.

A great self-experimentalist on ketosis, Dr. Peter Attia,
interviewed by another great LCHF expert, Dr. Andreas
Eenfeldt. In the links section, I included links to their
respective blogs.

Where is this sugar coming from? Since I already started being super strict in avoiding carbohydrates, my blood sugar couldn't have come from food. The other possibility is that my body started making glucose by itself. You may have not known it, but this is possible. Actually, it happens when body runs out of food glucose, but there are still proteins available. Through a metabolic process that I haven't yet addressed in my blog, we can actually turn protein to glucose. This glucose, just as carbohydrates coming from food, also raises our insulin, jeopardizes our ketosis and interrupts our fat burning process.

Happily, I was taking some notes about my nutrition in the past few weeks. I found out that on average, I gained 65% of calories from fat, about 30% of calories from protein and about 5% from carbohydrates. The question is: is this ratio really and LCHF diet?

According to a great expert on nutritional ketosis and an even greater self experimentalist, Dr. Peter Attia, we can achieve nutritional ketosis sweet spot by respecting the following three criteria:

• at least 80% of your calories should be coming from fat
• you should keep your carbohydrate intake below 20 grams per day
• you should keep your protein intake below 150 grams per day

In short, I call it the 80-20-150 rule. It is quite obvious that I failed to follow two out of the three criteria for the majority of the past two weeks. I could say that I was eating "LCMF" (low carb - medium fat) and not LCHF. So it seems that it is not LCHF that has let me down, but it was me not doing it properly. Conclusion: I should eat (even more) fat!

Plans for week 6

In the coming week, I decided to be more strict on the 80-20-150 rule. I will pay more attention on the amount of meat and other protein I eat. I will also cut back significantly on cheese and introduce more vegetables. I suspect that eating plenty of vegetables will help me a lot in following this rule, since a well greased bowl of salad is nutritious and contains over 90% of fat. Definitively a fantastic dish to smooth out any protein spikes.

I will also purchase a device for measuring blood ketones and write a more specific post on how to follow the 80-20-150 rule.

That concludes my week 5 report. It was less successful as I hoped it would be, but it was very educational. If you like my blog, please share it on Facebook or Twitter. It is really easy, just click the social network icon below. Also, if you would like to comment on what I am saying or suggest a diet-related topic you are interested in, feel free to put in in the comments below.

I wish you a nice, successful and healthy week!

My fourth week on LCHF

My fourth week on LCHF lifestyle is over. I have to say, time is really flying on this sort of nutrition. I am feeling like I'm repeating myself, but I am really happy to be still able to say that:

This week, my progress slowed downed a bit, but I
think that for a good reason.

• my weight is going down
• my waistline is less and less
• I am feeling great
• I have never been hungry

My progress has slowed downed a bit though. In the last week, I have lost 0.2 kgs and 0.5 centimeters of waistline. But I believe I know the reason.

First of all, nearly every day, I had a pretty hefty late night dinner. I had a bit of a chaotic work schedule and I couldn't manage to eat during the day, so I had some cheese, sausages, pork and similar goodies. I also ate less vegetables and more meat, which means more protein. But, all in all, eating such goodies late night every day and not gaining any weight is still a fantastic result, don't you think?

Second, I had two intense exercise sessions with my fitness trainer. I am pretty sure I have gained a few grams of muscle mass and burned some fat.

Finally, I spent a lovely weekend with my partner and my friends. We tasted some great wine and I decided not to hold back. Since wine contains residual sugar and alcohol, it's possible that I produced some triglycerides and interrupted ketosis. But again, it was totally worth it.

So, let's summarize. Heavy and tasty late night dinner every day, two evenings of exercise and a wild weekend, and still a little bit down on weight as well as on waistline - isn't it fantastic?! If I was eating carbs, I think I would be about 2 kilos up after a week like that.

News about Sam Feltham and his "supersize me" experiment

Sam Feltham after a 3 week LCHF "supersize me" diet. Although
overeating and consuming lots of fat, there is
is nearly no difference between day 1 and day 21.

In my post about the second myth about diet, I mentioned Sam Feltham and his experiments with diet. You

may remember: Sam went on a 5.800 calorie per day LCHF diet for three weeks. Even though he ate almost twice as much as he needed, he only gained a bit over one kilogram and actually lost a bit of waistline.

Sam Feltham after a 3 week high carb low fat "supersize
me" diet. His overeating of carbs is well visible. A very
nice illustration that not all calories are the same.

Well, this week, Sam completed another experiment. He was on a 5.800 calorie per day junk food diet, similar to diet in the movie Supersize me. On this high carb, low fat diet, he gained 7.1 kilograms and 9.25 centimeters of waistline. Think about that for a second: same amount of calories, same number of days, same person, but different food. And the difference is huge. You can see how Sam's body changed at both experiments throughout the diet.

Sam is now on his third experiment. In order to loose weight that he gained on his last diet, he switched back to an LCHF diet. He eats the same amount of calories as he burns per day according to a basal metabolism formula. But despite he is eating normally (only restricting carbs), he lost over 4 kilograms in the first week. You can follow Sam's daily progress on his video blog.

I'd say, another victory for LCHF. I'll definitively keep on going. Also, I'll appreciate your feedback. If you would like to say or ask something, just write it down in the comments.

I wish you a nice and successful week!

Myth 3: Cardiovascular problems are caused by saturated fats such as butter and pork fat

The cover from Time magazine published on
March 26th 1984 has painted cholesterol into
the major cause for cardiovascular problems
in the eyes of general public. Even though it
contributed to starting the "health craze",
30 years later, cardiovascular problems are
on an all-time high.

Let's take a look at this last controversial statement I have put in my first post "The more I tried the more I failed". I made a little experiment with my friends last week and asked them how would they feel about their health risks if they started eating lots of butter, bacon, eggs, coconut oil, heavy cream etc. They all said that they would get very concerned about their cardiovascular system and most of them labeled my idea everything between very risky and downright insane.

Then I asked them how do they know that eating a lot of fat increases the risk of cardiovascular problems. Again, their answer was unanimous. It's everywhere in the media, everyone is buying low fat food, all the doctors are saying it... OK I thought, that is indeed a strong argument, if everyone is saying it and doing it. But: why are more and more people dying because of cardiovascular problems? Are we really so sure that things are going in the right direction?

First of all, apologies for a long and perhaps complicated post

Not being a medical doctor and not even a certified nutritionist, it certainly is a challenge to write about human metabolism. It is a very complex system which combines the power of several organs, hormones, enzymes and also our nutrition. So I will begin this discussion by summarizing the key points I want to make. Although I wish you would read this entire post, you may as well check out the following key discoveries:

• the idea that eating food rich on cholesterol is a major cause of cardiovascular problems is not supported by scientific observations of human (not animal!) responses to different diets;
• the amount of cholesterol in our blood stream is virtually independent on the amount of cholesterol that we eat;
• cardiovascular problems are caused by lipoproteins, which have a role of a transport system for triglycerides and cholesterol;
• only one type of lipoproteins is dangerous, due to its chemical structure and size;
• if concentration of dangerous lipoprotein is low, there is little risk for cardiovascular disease;
• concentration of dangerous lipoprotein in our blood is nearly independent on the amount of fat and cholesterol we eat, however it depends a lot with the amount of carbohydrates;
• as a consequence of that last point, people on carbohydrate diets are in bigger risks of cardiovascular problems than people on LCHF diet;

In order to understand these points, it is important to first be clear about the key players in cardiovascular problems.

What really causes cardiovascular problems?

A very bad case of atherosclerosis.
The arthery wall is severely damaged by
chronic inflammation and is covered with
plaque which was created in body's
attempt to stop the inflammation.

The root cause of many cardiovascular problems is atherosclerosis. Atherosclerosis is a process where plaque is built inside arterial walls, along with an ongoing (chronic) inflammation of that area. Because of strong inflammation, muscles around arteries contract, increasing our blood pressure. Furthermore, plaque is an obstacle to normal blood flow, increasing blood pressure even further. Finally, when plaque grows a lot, it can completely jam an artery. Or, a piece of plaque may brake away and start travelling around our body, until it gets stuck in some narrower blood vessel and give us a stroke. So, the most common cardiovascular problems like heart attack, stroke, increased blood pressure are all a consequence of atherosclerosis.

Sure... But atherosclerosis is caused by fat and cholesterol, right?

Surprisingly, no! Atherosclerosis is not caused by fat nor by cholesterol. I know you have been told this thousands of times by all sorts of people, but it just isn't true. The thing is that cholesterol and triglycerides are not swimming around in our blood freely, because they are not soluble in water (nor in blood). In order to transport them around our body, we have a special transport system which consists of lipoproteins.

It is quite possible that you have never heard of a word "lipoprotein" before. But perhaps you have heard of LDL and HDL. Word on the street (and in most medical clinics) is that LDL is "the bad cholesterol" and that HDL is "the good cholesterol". They say that you should have plenty of the good cholesterol and as little as possible of the bad cholesterol, which causes artherosclerosis. That's not very far from the truth, but they haven't told you one important thing: LDL and HDL are not cholesterol, but two kinds of lipoproteins.

Say "hello" to lipoproteins

Lipoprotein is a molecular container. It's outer shell consists
of lipids (green circles with yellow tails) and proteins (larger
circles of different colors). Inside lipoproteins there are
molecules of triglycerides and cholesterol. They are
completely isolated from the rest of the body.

HDL stands for "High Density Lipoprotein" and LDL stands for "Low Density Lipoprotein". Even though general public opinion is nearly unanimous, that HDL and LDL are cholesterols, that is very very far from the truth. It is like saying that a Mercedes Benz and an Aston Martin are two sorts of trees. That would be total nonsense, since we all know that they are car manufacturers. And in the same fashion, HDL and LDL sure as hell are not cholesterol, but are lipoproteins, which have a completely different chemical structure and purpose.

Things you should know about lipoproteins

Think of lipoproteins like of boxes or containers. Even better, think of them as boats carrying around cargo. I borrowed this analogy from Dr. Peter Attia, whos excellent lecture of cholesterol is available at Youtube. I included a link at the end of this post, I warmly advise you to take a look at it.

What are lipoproteins carrying?

In short, they carry triglycerides ("fat" molecules) and (real) cholesterol molecules. The reason why it is necessary to transport triglycerides and cholesterol around as cargo is that they are not soluble in water, nor in blood. If there were no lipoproteins, cholesterol and triglycerides couldn't be transported around our body and that would be a very very bad thing. Depending on their structure, there are 5 different kinds of lipoproteins:

• Chylomicrons
• very low density lipoproteins (VLDL)
• intermediate-density lipoproteins (IDL)
• low density lipoproteins (LDL)
• high density lipoproteins (HDL)

An illustroations of different kinds of lipoproteins and their sizes. The bigger the size, the higher proportion of triglycerides.

As you can see, lipoproteins are not just LDL and HDL. If you have been reading this blog thoroughly, you may remember that I have already mentioned chylomicrons in Myth 1. To refresh your memory, chylomicrons transport triglycerides from our gut into our bloodstream and deliver them to our cells. If we have insufficient glucose, then these triglycerides are delivered to cells to be burned as energy, which is obviously a desired thing for overweight people. Otherwise, they are deposited in our "fat" cells as fat, which us the less desirable pattern.

VLDL has exactly the same role as chylomicrons, with and exception that the triglycerides carried by VLDL are coming from our liver, not from our gut. In the liver, our body produces its own cholesterol (which is 75% of all cholesterol we require). Furthermore, when there are abundant glucose molecules floating around, our liver creates triglycerides to be stored as fat. So you can think of VLDL as a transport system for triglycerides and cholesterol which our body produces by itself, while chylomicrons transport what we eat.

Since cholesterol is very important for normal functioning of our body, our liver will always create all the lacking cholesterol. If we eat little fat and cholesterol, than the majority of triglycerides and cholesterol will come from our liver and the concentration of VLDL will go up. Alternatively, eating more cholesterol and triglycerides reduces liver activity and concentration of VLDL, but the number of chylomicrons go up.

Once VLDL and chylomicrons our in our bloodstream, they follow the same metabolic process. Triglyceride and cholesterol cargo is delivered to cells. As they flow around our bloodstream, lipoproteins gradually release their cargo and become small and smaller. To be precise, they also exchange proteins, but that part is quite complicated and not so important for the point I am trying to make. When triglycerides are delivered, VLDL and chylomicrons transform into IDL, and then LDL. IDL doesn't last very long and is not important in cardiovascular issues, but LDL is. You may think of LDL as a grandchild of VLDL. It is a cargo ship at the end of its journey, where most of the cargo has been delivered. Hence, LDL particles are smaller than VLDL.

For know, I won't be mentioning HDL, except that is a different kind of lipoprotein. It is still a carrier of triglycerides and cholesterol, but it is created from a different sort of protein than VLDL, IDL and LDL and acts in quite a different way.

VLDL and LDL are both considered to be "the bad cholesterol". They are prone to oxidation and they are just the right size to penetrate into arterial walls and get stuck there. On the other hand, chylomicrons, IDL and HDL do not cause atherosclerosis. And since we now know that VLDL is coming from our liver, when it creates its own cholesterol and triglycerides, it seems logical to conclude that we should be on a diet that doesn't encourage production of VLDL.

But what about LDL? Did you know that there are two different kinds of LDL? Neither did I...

Introducing LDL-C and LDL-P

An illustration of LDL-C (left) and LDL-P (right). For the
same amount of total cholesterol, we need a larger
number of LDL-P, comparing to LDL-C.

LDL-C and LDL-P are both subclasses of LDL. Remember, they are both pretty much depleted of triglycerides and are carrying mostly cholesterol. LDL-C contains more cholesterol than LDL-P. Hence, LDL-C is bigger than LDL-P. This means that if we compared two people with the same total amount of cholesterol, but with different LDL particles, person A would have a small number of relatively large LDL-C particles and a person B would have a bigger number of relatively small LDL-P particles. According to Dr. Peter Attia: "there is no dispute that person A is at bigger risk than person B". So apparently, one kind of LDL is more dangerous than the other!

Analysis of 6 years of data of LCL-P and LDL-C along with associating risks has shown that people with low LDL-P and a not low LDL-C (not low means normal or high) were at lowest risk of cardiovascular problems (see blue curve on below chart). On the other hand, people with not low LDL-P and low LDL-C were at the highest risk (red curve). To simplify, cardiovascular risk was increasing with increasing LDL-P, while LDL-C doesn't have a large impact. Another study that spanned over 16 years (!) showed a similar result. If you would like to see further explanation and more data and/or if you are a fan of statistics, I suggest you to read this article.Or, you can just remember that although all LDL particles cause artherosclerosis, LDL-P is much more dangerous than LDL-C.

Comparison of risk factors of people with different concentrations of LDL-P and LDL-C. The red curve represents people with the greatest risk, which have low LDL-C and increased LDL-P. It is surprising to see that they are at an even greater risk than people with increased both LDL-P and LDL-C (yellow curve). At the lowest risk are people with low LDL-P and increased LDL-C.

Results of a 16-years long study of cca. 3000 people shows LDL-P has a much greater impact on cardiovascular risks than LDL-C.

So, to decrease cardiovascular risks, we should focus on decreasing LDL-P?

Correct! Since our body can produce all the cholesterol it requires and since this cholesterol has to be transported around, eating low cholesterol food won't lower your overall LDL. I found several experts hypothesising that the amount of cholesterol and subsequent LDL concentration is mostly defined by genetics and can not be largely regulated. This means, that the sum of all LDL particles may not be regulated much, but it doesn't mean that we can't affect the ratio between LDL-P (the "bad bad cholesterol") and LDL-C (the "good bad cholesterol"). I was very much surprise to discover that this ratio depends a lot on the amount of sugar we eat.

The role of sugar on concentration of LDL-P and LDL-C particles

In 2011, Peter Havel published results of his study on effects of simple carbohydrates on LDL, HDL and triglyceride levels. He divided his subjects in three groups, putting them all on a western diet consisting mostly of carbs, some fat and little proteins. Total calorie intake was low. The difference between groups was the kind of carbs they were given. Group A received 25% of their carbs as glucose, group B as fructose and group C in form of high fructose corn syrup (consisting of 45% glucose and 55% fructose). This was a very typical western diet, especially groups B and C, since we eat plenty of white sugar while high fructose corn syrup is a popular additive in processed foods. Even though it was a short study, results were very interesting, as you can see on below charts.

Impact of glucose, fructose and a mixture of fructose and glucose on lipoproteins, particularly LDL. Glucose has a much lower impact as fructose and a mixture of both.

This study revealed yet another surprise in a series of investigations of our metabolism. Group A (being on glucose) experienced only a slight increase of lipoprotein levels. Group B's increase  was much higher and increase of lipoproteins of group C was even higher. This study indicates that the worst impact on LDL, HDL and triglycerides has a combination of glucose and fructoce, which tends to be the combination us westerners are eating the most. From cardiovascular risk point of view, the least risky group was the group eating glucose. However, in our western reality, it is nearly impossible to eat so much glucose and so little fructose.

I hope that so far, you are a little bit more familiar with terms like cholesterol and lipoproteins. Studies presented so far show that against common public opinion, carbohydrate diets are risky because:

• our liver produces more harmful VLDL;
• fructose and a mixture of fructose and glucose increase harmful LDL;

So, if you want to reduce cardiovascular risks, carbohydrates surely are not the way to do it. But, even if carbohydrates increase cardiovascular risks, it doesn't automatically mean that saturated fats advised by LCHF diet doesn't. So let's take a look at another (and the final) study.

The role of saturated fat concentration of LDL-P and LDL-C particles

In 2003, a group of researches published results of a study made with 16 very obese people (body mass index over 39). They were put on ketogenic diet where 50% of calories were coming from saturated fat. After 6 weeks, these were the results:

Glucose, insulin, triglyceride and lipoprotein changes after
a six week diet rich in saturated fat. As you can see, the most
threatening factors for obesity and cardiovascular risks
decreased significantly.

• 5% drop of glucose
• 30% drop of triglycerides
• average size of VLDL particles decreased for 20% (probably because they recieved fat from nutrition, no longer so much from liver)
• slight decrease of total cholesterol
• slight decrease of total HDL
• slight decrease of concentration of LDL particles
• slight increase of average size of LDL particles
• 25% decrease of concentration of medium and small LDL particles (the bad LDL)

In summary, a diet rich in saturated fats significantly improved two major risks for atherosclerosis: triglyceride levels and VLDL levels, while LDL levels didn't change much. In terms of cardiovascular risks, this is a very good sign. The conclusion of this study was that insulin resistance of these people improved dramatically, despite the fact that their calories consisted of 50% saturated fat!

This last study shows that eating a highly saturated fat diet not only isn't dangerous for your cardiovascular system, but is actually very beneficial.

Putting it all together

After an extensive analysis of scientific data, obtained by observing people and not animals, as well as after looking at interpretations of this data by well recognized medical experts, my personal conclusion is that a diet rich in cholesterol and fat (including saturated fat), is not even nearly as dangerous as it is commonly believed. Contraversive, they seem to be quite beneficial. On the other hand, carbohydrates not only cause quicker generation of fat, but also stimulate production of harmful lipoproteins.

While I was writing this post, I was often surprised about how little do we really know about saturated fat and cholesterol, even though all kinds of information are only a couple of clicks away. I am now completely convinced that cardiovascular problems are not caused by saturated fat and cholesterol. The picture of pieces of fat and cholesterol molecules floating freely in our blood and clogging our pipeline, which is so often used to scare us away from butter and bacon, is completely unrealistic. I know now that atherosclerosis is caused by certain LDL particles and that the kind of LDL particles in our blood depends on our metabolic state. And finally, according to all the data as well as to my personal experience so fat, diets which are low on carbohydrates and high on fat (LCHF) are:

• easiest to follow;
• delicious;
• free of starvation and cravings;

and last but not least:

• good for your heart and arteries!

Further reading

Since cardiovascular risks is an important topic, I encourage you to gather more information on that subject. In particulat, I can recommend you to follow the works of Dr. Peter Attia, from whom I have borrowed most of the material for this post. 

• The Straight Dope on Cholesterol, a video of a lecture by Dr. Peter Attia
• The Great Cholesterol Myth, a video lecture of Dr. Jonny Bowden
• www.eatingacademy.com, a website and blog of Dr. Peter Attia containing plenty of useful information and scientific data about diet

My third week on LCHF

My LCHF statistics. Blue is weight in kilograms,
red is waistline in centimeters

I am through my third week and I am happy to report that things are going great! LCHF is so easy! I am never hungry, I eat properly good food and in the last three weeks, I haven't made a single error in following the diet. In fact, I have absolutely no desire nor thoughts to do so, because eating what I am eating now is sooooo gooood :)!

I lost another 0.6kg and am now on 107.6kg. My waistline is down 1.5cm. Altogether, I lost 2.6 kilograms and 5cm of waistline in three weeks.

I am especially happy about my waistline. Just take a string and measure 5 centimeters. It's shows! Isn't it incredible? Three weeks of eating tasty food like eggs, butter, pork products, cheese, oil, vegetables... No calorie counting, no schedule, no hunger and no cravings.

In addition to my diet, I also did two intense training sessions in the fitness studio, because I just felt like doing it. Every time after training, my weight stagnated for two days, which I believe is due to muscle growth and perhaps some additional water that is retained in muscles. But overall, 600 grams in a week is a great result, especially paired by a nice drop of waistline. I think I'll have to start looking for new pants soon :).

Grilled squid filled with mozzarella and ham.
Yet another reason why I love LCHF!

I was also made plenty of blood sugar measurements at different times of day. Since the objective of LCHF is to always keep blood sugar low, I was measuring it after meals in order to see how they affect me. I am happy to say that whenever I measured (and I did it a lot), my blood sugar was always between 78 and 92 mg/dl (which is between 4.3 and 5.1 mmol/L). This is well within normal limits, since it is considered normal to have fasting blood sugar between 70 and 100 mg/dl. So, to have blood sugar of 88 mg/dl after eating a nice portion of squid, filled with ham and mozzarella and topped with mayonnaise is pretty awesome. Later that week, even a sweet home-made panna cotta and a bottle of wine didn't raise it above 92 mg/dl. Awesome!!!

I also started writing an article about the third myth, which is about fatty food being bad for our cardiovascular system. Unless you have some special and rare genetic predisposition (and if you do, I suppose that you are already aware of that), this myth is really just a myth. It is totally wrong, low carb-high fat diets are in fact beneficial. However, it requires to understand a lot of complicated biochemistry processes it will take me a little bit more time to write it down for you in a simple and understandable way.

That's my experience of this week. It's going awesome and I'm looking forward for more. If you're interested in anything else I haven't written about or wish to say anything, feel free to put it into comments. Cheers!