Doctor Peter

06/07/2024

"...the 210,000 people in Estonia who contributed to the country’s biobank were given access to data such as their genetic risk for certain diseases — one of the world’s biggest efforts to return genetic results to research participants."

Project covering one-fifth of the country’s population is one of the largest-ever efforts to share results on genetic health risks with research participants.

04/03/2024

2024-03-04
DYNAMIC „STRETCHING”

According to the definiton, dynamic stretches use repetitive movements that take the muscles and joints through their full range of movement.
Here is one example: one type of arms swings.

1. Stand up straight with your knees slightly bent, your feet shoulder-width apart and your arms stretched horizontally to the sides.
2. Cross your arms at the front and then quickly bring them back as far as you can.
3. Repeat this back and forth movement until the set is complete.
https://www.spotebi.com/exercise-guide/arm-swings/

Such swinging dynamic movements can be performed for all joints and muscle. Some examples:
Bent Over Twist
https://www.spotebi.com/exercise-guide/bent-over-twist/
Side Lunge
https://www.spotebi.com/exercise-guide/arms-cross-side-lunge/

For more exercises see here: https://www.arthritis.org/health-wellness/healthy-living/physical-activity/other-activities/7-dynamic-warm-ups

Specific dynamic stretches combined with balance exercises is called the „Swedish Drill”
https://theschoolyardco.com/blogs/news/swedish-drill
applied in most schools in Europe as a warm-up routine at the start of physical eucation classes. It is a great way to start our workout, because Swedish Drill warms up the muscles and joints without hindering later performance.

Dynamic stretches, however, do not take your muscles through their full range of possible motion because of the „stretch reflex”. Receptors in the muscle arranged in muscle spindles detect changes in the length of the muscle. When the muscle is stretched too far muscle spindles send signals to the brain which then signal back to resist further stretch. Basically, the stretch reflex is a protective mechanism to keep the muscles at a normal, physiological length thus avoiding overstretching and tear.
To me dynamic strethcing is not real stretching but a good way to warm up muscles and joints before a workout.
I think real stretches to increase the range of movement are static.

What is Swedish Drill? Spend any amount of time scouring over Charlotte Mason literature, and you will find a unique term that most are unfamiliar with, Swedish Drill. The historical literature on Swedish Drill, often referred to as Swedish Gymnastics, is guaranteed to give you a good laugh. However...

14/02/2024

‘The crazy mRNA lady’

In 2013, biochemist Katalin Karikó was abruptly ousted from her tiny lab for not bringing in enough research money. “That lab is going to be a museum one day,” she hissed at her manager — oddly prophetic words. In her memoir Breaking Through, Karikó recounts her obsession with messenger RNA (mRNA), which she firmly believed could play a major role in medicine. Few colleagues agreed, and Karikó faced decades of hostility before her research helped to create a vaccine that saved millions during the COVID-19 pandemic. “This is a vividly written, absorbing memoir of a life filled with triumphs over near-constant adversity,” says reviewer Robin McKie.

This vivid account of the Hungarian biochemist who endured decades of derision before pioneering Pfizer’s Covid vaccine is a tribute to her tenacity and self-belief

03/08/2023

WHERE'S THAT FAT?
2023-08-03

As I wrote in a previous post, the body mass index (BMI) is suitable for assessing populations (e.g. men aged 18-20), but not for characterizing the health status of individuals. Recently, the American Medical Association drew attention to this (1). The reason for this is that the body mass index does not take into account the difference between women and men, or between different races, body composition, or age-related changes. The relationship between body mass index and health status is loose. A health risk is not simply the amount of adipose tissue, but the place where it is deposited. All tests indicate that fat stored in the abdominal cavity, the so-called visceral fat. Within this, the fat accumulated around the organs and in the organs (e.g. fatty liver) represents the real danger. That is why that a thin but big-bellied man with a normal BMI can be more concerned about his health than an overweight man with an even distribution of fat tissue.

Waist width
According to all studies, excess visceral fat is a risk factor for the development of cardiovascular diseases.
The amount of adipose tissue in the abdominal cavity can be accurately measured with imaging procedures, but this is a lengthy and expensive task. Waist circumference, however is easily measured and is quite closely related to the amount of visceral fat. The conclusion of a number of studies suggest that for “men, a waist circumference below 94cm (37in) is ‘low risk’, 94–102cm (37-40in) is ‘high risk’ and more than 102cm (40in) is ‘very high’. For women, below 80cm (31.5in) is low risk, 80–88cm (31.5-34.6in) is high risk and more than 88cm (34.6in) is very high. These are the guidelines for people of white European, black African, Middle Eastern and mixed origin.
For men of African Caribbean, South Asian, Chinese and Japanese origin, a waist circumference below 90cm (35.4in) is low risk, and more than that is ‘very high risk’ (there isn’t a ‘high risk’ category). For women from these groups, below 80cm (31.5in) is low risk, and anything above is very high risk.” (2)

Waist-hip ratio (3)
Merely measuring waist circumference cannot be sufficient for two reasons. One obvious reason is that tall people may have larger waists than short people, even if their abdominal fat is not greater in proportion to their total body weight. The other, less obvious reason is that while the excessive amount of visceral fat is indeed a risk factor, the adipose tissue stored on the buttocks and thighs can even protect against cardiovascular diseases (4). Because of all this, the measurement of hip circumference was introduced in addition to waist circumference. The ratio of the two is more closely related to the risk factors (3).
Here I present only one table from (5).

Health risk Women Men
low 0.80 or lower 0.95 or lower
moderate 0.81-0.85 0.96-1.0
high 0.86 or higher 1.0 or higher

In summary, excess visceral fat is indeed a risk factor. The amount of visceral fat is not closely related to BMI. However, it is related to body shape, which can be assessed as an index calculated from body height, mass and waist circumference (6). If you do not like measurements simply look honestly in the mirror and you can get an impression of fat distribution.

1) AMA: Use of BMI alone is an imperfect clinical measure
https://www.ama-assn.org/delivering-care/public-health/ama-use-bmi-alone-imperfect-clinical-measure

2) Why your waist size matters
https://www.bhf.org.uk/informationsupport/heart-matters-magazine/medical/measuring-your-waist

3) Waist–hip ratio
https://en.wikipedia.org/wiki/Waist–hip_ratio

4) Waist and hip circumferences have independent and opposite effects on cardiovascular disease risk factors: the Quebec Family Study
https://pubmed.ncbi.nlm.nih.gov/11522554/

5) What Is the Waist-to-Hip Ratio?
https://www.healthline.com/health/waist-to-hip-ratio

6) Body shape index
https://en.wikipedia.org/wiki/Body_shape_index

17/07/2023

NEW BODY MASS INDEX: WE ARE NOT STICKS
2023-07-17

A Belgian astronomer and polymath, Adolphe Quetelet, developed the body mass index (BMI) in the mid-19th century. BMI is easy to calculate: body weight (in kg) divided by height (in cm) squared. There are plenty of BMI calculators on the internet, with which you can easily determine your body mass index. Here is one such calculator:
https://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmi-m.htm

Quetelet believed that the body mass index was suitable for characterizing populations. And he was right, it was used for this later and especially in the last 30-40 years. Correlations have been found between high BMI values and the likelihood of developing diabetes, high blood pressure, cardiovascular disorders or cancer. These correlations mean that the risk of diseases is higher in the group with a high body mass index. It is important to note, however, that not all individuals with high BMI will be sick, so as Quetelet thought, BMI is suitable for characterizing populations. It never occurred to him that it could be used to characterize the health status of individuals, even though this done routinly. The thinking behind applying BMI to individuals is that someone whose BMI is too high may not necessarily get sick, but the risk is high. I won't bore you with tables here, the calculator shows the categories in use today, from severe underweight to obesity.

We're not the same
BMI is not suitable for characterizing individuals. It is not simply body weight that predisposes to disease, but the amount of fat, especially the fat accumulated in the abdominal cavity. A bodybuilder's mass can be high even if he has accumulated very little fat - for him, the being "overweight" comes from the mass of muscles. The reverse is also true: a thin-boned person with little muscle may have a BMI in the "healthy" range despite having a lot of abdominal fat.
Another problem is that according to several studies, people who are slightly "overweight" have a better life expectancy than those whose BMI is in the desirable range. I wrote about this with the title “BEING OVERWEIGHT DOES NOT MEAN EARLY DEATH”.

Maths: we are not sticks
In principle, the "healthy" range should increase linearly as a function of body height. However, if you look at the graph attached to the Wikipedia entry, it is clear that direct proportionality does not hold.
https://en.wikipedia.org/wiki/Body_mass_index

The TTI allows more weight for shorter than average people and less for tall people. There is a simple mathematical reason for this. Quetelet calculated by the square of the height, not because it was the best approach, but because, in the absence of computers, simple squaring could be done on paper. However, now we have computers and we are three-dimensional beings. Of course, increasing weight to a cube would be an exaggeration, because most of us are not balloons.
An Oxford mathematician, Nick Trefethen, proposed a new formula: the right exponent is exactly between 2 and 3. He also stuck a constant in the equation, with a value of 1.3, which ensures that the BMI of people of average height does not change according to the new calculation.

BMI = 1.3*weight(kg)/height(m)^2.5

You can read Trefthen's explanation here: https://people.maths.ox.ac.uk/trefethen/bmi.html

Of course, a calculator was also created for the new BMI, which gives the new and traditional BMI values after entering the height and body weight. In addition, it also indicates which category your body mass index falls into according to the new or the traditional calculation. Compared to the traditional BMI, the new BMI allows a little more weight for taller people and a little less weight for shorter people.
You can find the calculator here: https://people.maths.ox.ac.uk/trefethen/bmi_calc.html

For much shorter tan average, e.g. a 155 cm tall person weighing 60 kg according to the traditional calculation falls in the healthy range, but according to the new method, it is considered being overweight. Similarly, for tall people, the difference is quite large. For example, a two-meter-tall person with 108 kg is overweight according to the traditional TTI, but still healthy according to the new calculation.
The new calculation method fixed the mathematical tangle, but it is also not suitable for estimating the health status of individuals. There are better ways to do this, which I will write about later.

14/07/2023

SUGAR = TUMOR?
2023-07-14

A German biologist named Warburg discovered in the 1920s that tumor cells absorb a lot of sugar compared to normal cells (1). The first step in breaking down sugar is the same in cancerous and healthy cells. In healthy cells, the first intermediate product enters the mitochondria and is further developed here in the presence of oxygen (oxidative phosphorylation). On the other hand, in tumor cells, the first intermediate product remains in the cytoplasm and evolves there, e.g. into lactic acid (anaerobic glycolysis). The Warburg effect or Warburg hypothesis, named after the researcher, is very surprising, because the efficiency of anaerobic glycolysis is only a fraction of that of oxidative phosphorylation. While the latter process produces 32 energy-carrying molecules (ATP) from a single sugar molecule, tumor cells produce only two. Healthy cells also need this inefficient process - but only in the absence of oxygen. During anaerobic movement, e.g. during the 100 m sprint, the muscle cells are not able to use the mitochondria for burning either - because "burning" requires oxygen - but when the run is over, the normal process is restored. This is why short-distance runners gasp for air at the end of the race.

A hundred years later, it is still not clear why aprox. 80% of the tumor cells behave so strangely. There are at least 4 hypotheses, which are nicely summarized in the second diagram of article (2). Of course, if we have 4 explanations for a phenomenon, we cannot know which one is the real one. However, the Warburg effect does exist, so much so that the location of cancerous tissues can be easily determined by examining the level of glucose uptake (PET scan after administration of radioactive glucose).

Intermittent fasting
Fasting has been used by people for thousands of years to overcome diseases. Fasting therefore results in not only spiritual but also physical purification. We know quite a lot about the mechanism of action (3). Two things are worth mentioning here. If we don't burden our body with digesting the products of 5 meals a day, it will have more time and energy to remove damaged cells (autophagy). From the point of view of malignant tumor, it is particularly important that most of the sugar reserve is used up during fasting, and the blood also carries less amino acids, so we practically starve the extremely voracious cancerous tissue. And the healthy cells - thank you - function well.
From the point of view of cancer patients, the surprising experience that the effectiveness of chemotherapy increases during fasting is of special significance. Patients also feel better if they eat less during treatment, which is important, but it's not just about that. The fight of the immune system against cancer cells increases, and the self-destruction of cancer cells (autophagy) also increases (3). Unfortunately, there are relatively few studies on this question. One of the reasons for this is that most hospitals insist on medication-only treatment, the other reason is on the patients' side: those who have never done it have a hard time getting started with intermittent fasting.

Lots of fat, little carbs
The ketogenic diet, which is low in carbohydrates and high in fats mimics in a way intermittent fasting. The usual western diet contains a lot of starches, e.g. bread, white rice, boiled potatoes, etc. With the usual diet, the daily calorie requirement is fulfilled by approx. 50% by carbohydrates (oh, egg dumplings, I miss you!). In a diet low in carbohydrates, this is only 5-15%.
Low carb - high fat diet does not exclude carbohydrates, and drinking lukewarm lard is not required. The diet simply excludes "fast" carbohydrates. Instead of potatoes or white rice, a large portion of salad drizzled with olive oil can be a suitable side dish. On the one hand, olive oil is a "good" fat, and on the other hand, all fats slow down the absorption of carbohydrates. A little more scientifically: carbohydrates of low glycemic index are "good" for us.
Although there are no extensive studies on humans, experiments on animals or in vitro tissues suggest that the ketogenic diet slows down, and in some cases stops, tumor growth (5-6).

Any caveats?
Recently, a report was published confirming that the keto diet does indeed reduce tumor growth, however, may cause pathological weight loss leading to death (7). In mice! Mice are handy :-( for experimentation, however, rodents have a very different metabolism from ours. Lack of large scale studies in humans is understandable: hospitals and patients alike are averse to the weird keto diet. However, there are quite a lot of anecdotal reports suggesting that cancer patients do not lose an abnormal amount of weight on the ketogenic diet. However, it is difficult to draw a final conclusion, controlled studies are needed.

THIS IS NOT MEDICAL ADVICE!
I'm a biologist, not a medical doctor. Above I summarised some scientific publications and popular articles reporting on them. I do not give medical advice. Ask your doctor for advice.

1) An Old Idea, Revived: Starve Cancer to Death
https://www.nytimes.com/2016/05/15/magazine/warburg-effect-an-old-idea-revived-starve-cancer-to-death.html

2) The Warburg Effect: How Does it Benefit Cancer Cells?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4783224/
Figure 2 for possible mechanisms: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4783224/figure/F2/

3) The Health-Promoting Effects and the Mechanism of Intermittent Fastinghttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC10005873/

4) Fasting and Cancer
https://www.healthline.com/health/fasting-and-cancer

5) Ketogenic diet in the treatment of cancer – Where do we stand?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7056920/

6) Ketogenic Diets and Cancer: Emerging Evidence
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6375425/

7) Keto diet may slow cancer tumour growth in mice – but not without potentially deadly consequences
https://theconversation.com/keto-diet-may-slow-cancer-tumour-growth-in-mice-but-not-without-potentially-deadly-consequences-207658

The diet was shown to accelerate onset of a severe wasting disease.

08/07/2023

BEING OVERWEIGHT DOES NOT MEAN EARLY DEATH

2023-7-8

Health at the population level is often assessed by the Body Mass Index (BMI). BMI is equal with the weight of the body in kg divided by the square of height in cm. The non-metric calculation is a bit more complicated, however, you can find calculators for both measures in the net.
US or metric units: https://www.calculator.net/bmi-calculator.html

My current BMI is 28.7 – too much beer in winter – and the calculator suggests I better lose 26 lbs to become healthy. Undoubtedly, I am overweight, but not yet obese. Clearly I need to lose some weight if I want live. Or not?

A recently published research confirms that death rate is clearly higher within the obese and underweight groups, however people with a little access weight fair quite well. Actually, death rate with a few extra pounds is somewhat lower than of people within the “healthy” BMI range.

How can we explain that?

1) People can become underweight because of facing some critical illness. The researchers corrected for this possibility by excluding data of people who died within two years of the initial survey.
2) BMI does not reflect the fat/muscle tissue ratio. Some people can be overweight without excess fat but much muscle. That might be true for body builders, however, they are a minority.
3) BMI says nothing about the distribution of adipose tissue. This is a real problem, mortality is not usually increased by a lot of fat, but by fat stored in the abdominal cavity. Therefore, it is important to measure waist circumference in addition to BMI. The authors did not collect such data.
4) People's weight changes with age, but the study is based on a single piece of data, the body weight reported 20 years earlier. There may be many who were overweight at age 40, but over the next 20 years they lost weight to their "healthy" range. This may be true, but of course the reverse can also happen.
5) Overweight people have some weight to lose weight in the event of a serious illness. I don't know how common this is, but this is exactly what happened to a friend of mine. Due to a stubborn infection, he was hospitalized for 3 months and during that time he lost about 20 kilos. He was lucky to have access fat.

The final conclusion of the study is that the body mass index alone is not suitable for characterizing the health status of individuals. It is still true that the very thin and the very fat are at greater risk, but this is no longer seems valid for the slightly overweight. The conclusion is consistent with the results of previous studies, e.g. with the fact that those at the upper end of the "healthy" BMI limits - especially at an old age - live longer.

HOW MUCH IS TOO MUCH?

It is not necessary to perform complicated calculations to determine the upper limit of a BMI that is generally accepted as healthy. My sergeant grandfather, who had never heard of the body mass index, but had to deal with the condition of recruits, said: the upper limit is simply the body height (in cm) minus 100. So for 160 cm - 60 kg, for 180 cm - 80 kg or for 200 cm - 100 kg.
BMI values are a bit biased because they were developed for people of average height and average weight. Shorter people are allowed more weight and tall people less than a healthy upper limit. This error was recently corrected, but I may write about it later.

THE POINT

It seems worthwhile to aim for the higher of the healthy BMI limits, but a few extra kilos above that does not represent a health risk – even though it doesn't look good in the mirror.

The original study:
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0287218

Brief news about the study:
https://www.newscientist.com/article/2381121-having-an-overweight-bmi-may-not-lead-to-an-earlier-death/?utm_source=Nature+Briefing&utm_campaign=a9a90bd7ab-briefing-dy-20230706&utm_medium =email&utm_term=0_c9dfd39373-a9a90bd7ab-43547793

A large US study has found that being overweight but not obese carried a slightly lower risk of dying within the study period than being a supposedly healthy weight

13/06/2022

2022-06-13
RESISTANCE TRAINING WITH HIGH BLOOD PRESSURE?

Traditionally, doctors advised hypertonic patients against any sort of weight lifting. Strenuous exercise in general, weight lifting especially increases blood pressure temporarily. So with high blood pressure it made sense to avoid additional stress on the blood vessels. Makes sense, but it is still wrong.
Research shows that resistance training can reduce blood pressure.
So the questions are:
Is it save to train with high blood pressure?
Can resistance training lower blood pressure?

THE EFFECT OF RESISTANCE TRAINING ON HIGH BLOOD PRESSURE

Before we get into it, I must note, that strenuous exercise is a risk factor for the rapture of intracranial aneurysm, which is a small ballooning of a blood vessel in the brain.
[research paper on risk factors: https://europepmc.org/article/med/21546472]
An estimated 2% of the US population have aneurysm, so chances are small that you have one. Still, people at my age, 70+, should be very careful when working out. That includes proper breathing (do not hold your breath) and good form. Additionally, I avoid exercises where my head would be much lower than my belly button.

On the basis of research the two questions can be answered together. No paper reported any injuries or cardiovascular events during any sort of training. It should be noted, however, participants exercised under supervision or they were trained prior to the experiments. That means they performed the exercises in proper form.

All research I am aware of reported a positive effect of resistance training on blood pressure. When reading the literature my biggest surprise was that high intensity workout, using relatively big resistance and low repetition number (6-9) posed no risk and had a positive effect on blood pressure.
[research paper: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8056164]
Although it is a pilot study with few participant, it is reassuring that elderly people being under regular treatment to control blood pressure could benefit from strenuous exercise.

On the other hand, the Taiwan Society of Cardiology does not recommend high-intensity exercise for individuals with uncontrolled hypertension (SBP > 160 mmHg) until BP has been controlled.
[paper: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9121756/]

Surprisingly, even isometric training has a beneficial effect on resting blood pressure.
[paper: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6727950/]
Isometric means the length of the muscles do not change during the exercise, the limbs and the body do not move. That is good news for those with osteoarthritis, force can be exerted without grinding the joints.

All research suggest that hypertension is not an obstacle in resistance training, on the contrary, working out might help to reduce blood pressure. Nobody suggests that body building is the best way to reduce blood pressure, the point here is that folks with controlled high blood pressure (under perhaps 160/100) can go ahead and exercise.

Physical exercise has been shown to have an important role in the prevention and treatment of arterial hypertension. However, the general exercise recommendations are time consuming, which might be detrimental to exercise adoption. Based on this, minimal ...

24/05/2022

RESISTANCE TRAINING: GYM MANNERS
Peter Kabai PhD
2022-05-24

Some elderly people would not go to a gym because of the fear to be ridiculed. However, people mind their own business in the gym and will not even look at my 70 year old body. If they do what I might get is a friendly smile. This is my experience in 3 countries (currently I have been staying for 5 months in Mexico (Hostel Casa de Paco in San Cris and visiting the gym Alterna Body Factory, just across the street).
So if you are a 60, 70 or 80 years old beginner you have no reason to be shy.

A YouTube video nicely summarises 10 things what to do and what not to do at the gym.

I am listing the 10 points under and then I comment/add a bit based on my own experience

The 10 rules are about

1) Wiping the machine after use
2) Ego lifting
3) Grunting
4) Using deodorant
5) Unsolicited advice
6) Cleaning up your weights
7) Exercising to close to the dumbbell rack
8) Spending too much time on the phone
9) Hogging up many pieces of equipment
10) Comparing yourself to others

See the video for details:
https://www.youtube.com/watch?v=JpD3_zxexcE

Hygiene: 1 and 4. I would add towel use. In Budapest (Hungary) it is compulsory in every gym I visited. In London it was not, some people use it, others don’t. Here in San Cristóbal (Mexico) it is written on the wall, but I have not seen anybody carrying a towel. So I don’t.

For your own sake: 2, 8 and 10. I would add in London I saw many guys texting for a long time while sitting on the machine thus blocking others from using it. It is not nice.

Annoying others: 3 and 5. I have never got any advice in London, nor here in Mexico, but received a few in Hungary, and yes, they were all wrong and dangerous.

Blocking others: 6, 7 and 9. It never happened in Budapest or London, except – as I mentioned - for some guys phoning while on the machine. Here in San Cristóbal all these are common. People usually work out right by the rack – maybe so that they can admire their bodies in the mirror. Additionally, sometimes guys do an exercise completely independent from the machine they occupy. For example, this morning a young chap was using dumbbells while sitting on a rowing machine. Even though there were free benches around.

Now Mexicans are jolly good and helpful fellows, so I can ask them even with my limited Spanish. Like this morning, there was a mask on an equipment I wanted to use, and you can never be sure whether it is a sign indicating that the person will come back or just pure ignorance. I asked around and the machine was freed up with a big smile. However, no smile can help that dumbbells are seldom put back on the rack in order. If I need two dumbbells of 10 kilos I can walk around for some time to find one and a minute to find the match. But hey, this is Mexico, the sun is shining!
This never happened in the two gyms I know in London. The sign on the wall might have helped: “If you are too tired to put the dumbbells back in place, ask the girls at the reception for help.” :-D

I would add an 11th rule about physical contact. Here in Mexico hugging friends is the norm. Never in my life have I received so many hugs like here in 5 months. Not often, but I can see lovers kissing each other lightly in between exercises. Never happened in London or Budapest. The gym is mainly about the body, so bodily contacts are frowned upon in most countries.

It is great to go to the gym with your partner, but leave the kisses for after the workout. The day after – if your workout is very hard.

These are 10 major gym mistakes that you want to avoid. Don't become one of the common gym stereotypes that make everyone uncomfortable. Learn to avoid the t...

23/05/2022

DIET: THE CALORIMETER IN OUR BRAIN
Peter Kabai PhD
2022-05-23

I had been slowly but steadily putting on weight during the pandemic. About 1 kg a month ending up with 104 kg body weight by my height of 180 cm means obesity. Wouldn’t it be nice to have a calorimeter in our brains to warn us when to stop eating? The good news is that we have such an instrument. The bad news is that the calorimeter underestimates the caloric intake. The question is, by how much?

The average American male gains about 8 kg between the age of 20 and 50. That is about 250 grams per year. Almost nothing. Of course, this is the average and whereas the weight of some people does not change much, others become obese during those years. Let us assume that a 170 cm tall male starting with normal weight of 70 kg ends up at 100 kg in 30 years. Now that is clinical obesity for him, although the yearly weight gain was only 1 kg.

Let us assume that all the weight he put on was in fat – which is an overestimation of fat gain. One kg of fat contains 7700 calories, which means about 21 calories extra daily. For someone with a daily energy expenditure of 2000 calories, 21 extra calories are about 1% miscalculation. Well within the range of error.

An egg contains 75 calories, so to get obese less than half an egg is needed above the calories burnt. Almost nothing. Isn’t it remarkable? Especially if we consider that some days we spend most of our time sitting by the laptop, other days we go for a hike, or do some running burning more calories.

Even in my case, the extreme fast weight gain during the quarantine, 1 kg a month equals to 7700 calories, which translates to about 250 calories extra daily. That is about 10% extra above to my daily energy needs. Now, that is big, but not extreme, however, led to an extreme weight gain in about two years.

Unfortunately the calorimeter in most of us underestimates – although slightly – our energy need. This is because during our evolution this inner meter was not calibrated to very palatable and energy dense foods and drinks what we have today. The foods of our ancestors on the savanna contained less calories, except for honey, but honey was not an everyday treat. Savanna hunter-gathers, like the Hadza today, eat almost everything edible except for a few taboo foods.
https://journals.sagepub.com/doi/pdf/10.1177/147470490900700409
And they have to, because food is unpredictable. When food is abundant, as following the kill of a large animal, they eat more than needed for that day and burn this extra energy in leaner times.

So these two factors in our evolution, food poor in energy and the need to eat more than needed when food is available can explain partly the present day obesity epidemic. Our inner calorimeter still works but can be deceived by the carefully designed products of the food industry.

The Hadza rarely mix different food types. After a hunt they eat meat. When the collect honey they eat honey. How much meat can you eat without bred, or how much honey can you eat in itself? Not a lot. The food industry knows this and makes processed food highly preferred by mixing major nutrients (protein, carbs and fats), and by adding some flavour enhancers (sugar, salt, monosodium glutamate etc.). So we get very palatable and energy rich food. And we overeat. And obesity has become a real epidemic.

Our inner calorimeter is deceived by the food industry.