Food, Water, Air, Gravity, Physical Activity and Weight Gain/Weight Loss

As long as we have been able to trace human understanding about food, it was always known that food is essential for sustaining life and at the same time, food intake usually leads to weight gain and the absence, or harsh restriction, of food intake leads to weight loss.

On the other side, human understanding had always been that some people gain weight more easily and some not so easily, and that many never gain excessive weight, regardless of how much food they eat and how much they are physically active or inactive.

It was always a little bit strange that some people always have the same weight at a time when there was an abundance of food, but people didn’t reach to the conclusion that intake of food is not an important factor in weight regulation of the body because on the other side, there were plenty of examples of starvation where the absence or harsh restriction of food intake causes weight loss by everyone (among naturally thin, normal weight or overweight) and when regular food intake leads to weight gain among everyone who had lost weight due to starvation.

The examples of starvation clearly shows that extreme reduction of food intake for a considerable amount of time will cause weight loss to the point of skeletal proportion by everyone; regardless of whether he is underweight, normal weight or overweight.

  1. It should be kept in mind that not all people affected by starvation are able to reach the point of skeletal proportion, because many of them will die from starvation before they lose a significant percentage of their body weight.
  2. Also, it needs to bear in mind that apart from a few anecdotes, severe obesity was unknown to any previous generation in recorded human history. Particularly, among children and young people, obesity was non-existent.

The next fact is based on another example from real life and it shows that if people affected by starvation to the point of skeletal proportion get enough food to eat on a regular basis, in a short time they will regain weight. That fact strengthens the wrong conclusion that still the absence of food intake will cause weight loss, and that food intake will cause weight gain among everyone.


It should be kept in mind that not all people will recover from starvation. Many of them will die despite resuming normal food intake; also many of them will suffer irreversible or long lasting health consequences.


One contradictory fact has come from human space travel. Since the beginning of human space travel, it was known that weightlessness alters the regulation of body weight. During the course of being in a weightless environment, a human body is affected by atrophy. In weightlessness, the human body loses muscles mass, bones mass and fat mass.

In weightlessness, air, water and food are essential to sustain life but it does not have any significance for body weight regulation.

A regular or an increased food intake in weightlessness does not cause weight gain among anyone.


Even more striking is the fact that a regular or increased food intake in weightlessness won’t prevent or even slow weight loss (atrophy of the muscle and bone tissues, and also atrophy of the fat tissue).


One other important fact is that in weightlessness, the human body loses strength.

While in a weightless environment, cosmonauts and astronauts spend a great amount of time doing exercises on specially designed exercise machines and devices, and the reasons for that is to slow the atrophy of the muscle tissues, fat tissues and bone tissues and at the same time, to slow the loss of the body’s strength.

In a weightless environment, the only way to slow atrophy of the body mass, and to some extent to counteract the negative consequences for the body’s strength and health caused by the absence of gravity, is to provide the body with mechanical stimulations by working on specially designed exercise machines.

Working against the forces of exercise machines and specially designed devices enables cosmonauts/astronauts to some extent slow down the loss of the body’s strength.

Mechanical stimulations produced by working on specially designed exercise machines and devices enable (to some extent) them to counteract the dissipation of the muscles, bones and fat mass.

On Earth, the body has weight because of the pull of gravity and the muscles and bones are (for most of the time in a subconscious level) used to support the body weight.

In a weightless environment, a body does not have weight and because of that fact, the muscles and bones can’t be used to support the body weight.

The reasons for the decline in strength in weightlessness and on Earth are nearly identical. In a weightless environment, the reason for the strength of decline is the absence of the use of the bones and muscles (absence of physical activity) and on Earth, the reason for decline of strength of the muscles and bones are the insufficient use caused by insufficient physical activity and/or extreme efficiency of supporting and carrying our body weight.


The atrophy (regression) of the muscle, fat and bone mass in a weightless environment happens because of the absence of mechanical stimulations on the fat, muscle and bone tissues.


On Earth, the ground impact forces appear each time when we step with the foot on the ground while walking, running and jumping. These impact forces reverberate from the bottom of the feet throughout the rest of the body, providing mechanical stimulations to the body.

Walking is the act of propelling and transferring the body weight from one leg to the other leg. Walking with an unbalanced gait has the consequence of, to some degree, falling from one leg to the other, which leads to the production of stronger ground impact forces.

This means that one kind of mechanical stimulations (Dynamic Mechanical Stimulations) on the body is induced by the ground impact forces produced by walking, running and jumping.

Another kind of mechanical stimulations is produced by the body’s own weight (Static Mechanical Stimulations). A simplified example would be; the upper body weight provides mechanical stimulation to the legs.

In reality, the weight of each particle of the body that is above provides mechanical stimulations to the particle that is below. In a standing position, the weight of the head and neck provides mechanical stimulations to the rest of the body. The weight of the upper part of the body provides mechanical stimulations to the lower part of the body.

In a sitting position, the upper body weight only partly provides mechanical stimulations to the upper part of the legs, and does not provide mechanical stimulations to the lower part of the legs.

In a lying down position, the upper body weight does not provide mechanical stimulations to the lower part of the body (but still the weight of each particle that is above provides mechanical stimulations to the particle that is below).

One other fact that needs to be taken into consideration is that in a sitting position, we are not using the legs to support the weight of the upper part of the body against the pull of gravity. Prolonged sitting will lead to decreased strength for the legs (due to a lack of use), and a decrease of the muscle, fat and bone mass in the legs (due to insufficient mechanical stimulations).

The act of using the bones and muscles is a factor that maintains and builds the strength of the bones muscles. At the same time, the weight of the body and the use of the muscles and bones (physical activity) provide mechanical stimulations to the bone mass and to the muscle mass, and that is one of the factors that maintains the existing bone and muscle mass and builds new ones.

Here on Earth, by standing, and partly by sitting and by performing everyday locomotion, we use (on a subconscious level) the muscles and bones to support our own body weight.


a) In a weightless environment, the body does not have weight.

b) In a weightless environment, we cannot use muscles and bones to support our own body weight because the body does not have weight.


There is a clear contradiction between the intentions of doing exercises in a weightless environment, and here on Earth. In a weightless environment, it is necessary to do exercises to prevent weight loss and here on Earth, people do exercises to induce weight loss.

This shows that there is something wrong with the intention of doing exercises here on Earth.

Doing exercises in a weightless environment and here on Earth with the intention to maintain and/or to improve the strength of the body, and to maintain or to improve the body’s composition concerning muscle and bone mass is a reasonable intention.

It’s obvious that doing exercises in a weightless environment with the intention to lose fat mass would be a mindless intention because in a weightless environment, the human body not only involuntarily loses muscle and bone mass, but it involuntarily loses fat mass.

Doing exercises here on earth is accepted as a reasonable way to lose excessive fat mass. The question is; is it here on Earth that the intention of doing exercises to lose fat mass is a mindful one, or is the human understanding of the mechanism that regulates body weight and appetite insufficient?

This means that by the absence of mechanical stimulations on fat tissues, the body will not only be unable to build new fat mass, but it will also be unable to maintain existing fat mass.


The examples of how weightlessness affects the weight regulating mechanism among cosmonauts and astronauts shows us that by the absence of mechanical stimulations, the body will not only be unable to build fat mass, muscle mass and bone mass but will also cause the loss of muscle, bone and fat mass.


Here on Earth, the downward pull of gravity constantly acts on our body (on each particle of our body), but the presence of the pull of gravity alone is not enough to maintain the existing mass of the bone, muscle and fat tissues.

We have plenty of examples where people are affected by involuntary weight loss, and we can’t blame weightlessness because it happens here on Earth. Examples include; the elderly, people affected by simulated weightlessness, people with long standing illnesses, and people affected with certain types of injuries are involuntarily losing weight.

The examples here on Earth shows that among people with long standing illnesses, the elderly and people affected with certain types of injuries, the absence of sufficient mechanical stimulations (concerning strength and duration) on fat tissues will cause atrophy of the fat mass.

Based on the understanding that the increase of food intake causes weight gain, and that the reduction of food intake causes weight loss, the occurrence of weight loss from the elderly, people affected with long standing illnesses and people affected with certain types of injuries, was always wrongly understood as a direct consequence of a reduction of food intake caused by an absence of appetite.

When we take into consideration that excessive mechanical stimulation on the body causes weight gain (hypertrophy) and that the absence or insufficient mechanical stimulation on the body causes weight loss (atrophy) will give us this explanation. Weight loss by the elderly, people affected with long standing illnesses and people affected by certain types of injuries is due to a decrease of strength and/or duration of mechanical stimulations on the body, below the required level of what is necessary for maintaining the existing body mass.

The absence of the required level of mechanical stimulations on the muscle, bone and fat tissues causes the process of atrophy.

The presence of atrophy causes a decrease in appetite, and a decrease in appetite causes a reduction of food intake.


Weight loss by a patient who undergoes weight loss surgery till now is attributed to a forced reduction of food intake.

The fact is that weight loss surgery forces a reduction of food intake, but it is also the fact that weight loss surgery forces modifications on the gait and body posture.

The weight loss surgery forces modifications on the gait and body posture in a similar way as certain types of injuries. In both cases, the patient is forced to reduce physical activity and is forced to increase the efficiency of locomotion, and the efficiency of supporting the body weight against the pull of gravity.

Decreased physical activity, along with increased locomotion efficiency, and increased efficiency of supporting the body weight against the pull of gravity causes a decreased supply of mechanical stimulations on the body.

Among patients who undergo weight loss surgery, weight loss can be attributed to only one factor, and that is the reduction of mechanical stimulations on the body below the level required for maintaining existing body mass.

The absences of mechanical stimulations or the reduction of their strength and/or duration below the level required for the maintenance of the existing fat mass will result in weight loss of the fat mass.

The occurrences of any weight loss by humans, and also by animals, are due to reduced strength and/or duration of mechanical stimulations below the maintenance requirement.

The occurrences of weight gain among humans and by animals are due to increased strength and/or duration of mechanical stimulations above the maintenance requirement.


The mechanisms underlying weight loss among people who undergo any kind of weight loss surgery (Bariatric Surgery etc.) is identical to the mechanism underlining involuntary weight loss by people affected with certain types of injuries.


Side note:

The mechanism of weight loss induced by weight loss surgery is explained in the article: “The Underlining Mechanism of Weight Loss Induced by Bariatric Surgery (Weight Loss Surgery), published in the book; Modern Science of Biomechanics & Weight Gain and Weight Loss (in the Part 1, Chapter 11).


It is known that many people who follow some program for weight loss based on the restriction of calorie intake achieve significant weight loss. That fact misleads almost everyone to the conclusion that a restriction of food intake directly causes weight loss.

The simple explanation of how a reduction of food intake causes weight loss is;

  1. A restriction of food intake causes hunger.
  2. Prolonged time of hunger causes weakness to the body.
  3. Weakness increases body awareness.
  4. When the body is for one or another reason (illness, inadequate food uptake etc.) affected by weakness, the first response is to reduce physical activity and the second is to do everyday locomotion and other physical activities in a more efficient way.

Weakness and increased awareness of the body are responsible for increased locomotion efficiency by improving gait and posture which leads to a decrease of strength of the mechanical stimulations produced by walking, running, sitting and standing.

Increased efficiency of locomotion and increased efficiency of supporting our own body weight against the pull of gravity has the consequence of a decreased induction of mechanical stimulations to the body, particularly in the fat tissues.

Decreased strength and /or duration of mechanical stimulations in the body, below the level required for maintenance, is a factor that is responsible for weight loss.

A more balanced gait means more efficient locomotion. For example, by standing still on two feet while maintaining an upright body posture, we use the bones and muscles to support the body weight against the pull of gravity.

In a still standing position, while maintaining a good body posture, we don’t induce mechanical stimulations in fat tissues.

Reduction of food intake without reducing the level (strength and/or duration) of mechanical stimulations on the body will not cause any weight loss, because the body will efficiently digest food and fewer calories will expel through the excreting mechanism. That is the reason why some people are unable to lose weight following a diet based on a moderate or even severe restriction of calorie intake.


Harsh restrictions or an absence of food intake for a considerable amount of time without a decrease in the level of strength and/or duration of mechanical stimulations in the body will not cause weight loss, but a loss of life.


Among naturally thin people, intake of food on a regular basis, and occasionally or frequently excessive food intake, does not affect the gait and body posture.

The fact that increased physical activity by many people causes weight loss leads to the wrong understanding that weight loss occurs as a direct consequence of spending more energy out, than what is in the food intake.

It is known that for the time of doing exercises, the body does not lose weight. After exercise or strenuous physical activity, the body maintains an elevated heart and breathing rate for a few minutes and after that, regains the pre-exercise level of breathing rate. Post exercise consumption of oxygen does not explain weight loss.


Post exercise weight loss is due to the increased efficiency of supporting and carrying own body weight.


Improvement of postural strength, followed by an improvement in body posture positively affects the efficiency of locomotion and the efficiency of supporting the body weight against the pull of gravity, and those are the facts that are responsible for weight loss.

Another fact is that increased physical activity in many cases leads to an improvement of postural stability and motor skill, which positively affects the gait and posture.

When doing any physical activity while maintaining a balanced gait and good body posture, mechanical stimulations are induced to the bone and muscle tissues, but not in fat tissues.

Working against the pull of gravity with an unbalanced gait, and/or poor body posture, induces mechanical stimulations not only in the bone and muscle tissues, but also in fat tissues.

The solidity-strength of the bones and muscles is what supports the body weight against the pull of gravity.

The presence of mechanical stimulations in the bones and muscles is what maintains the existing mass of the bones and muscles tissues. By maintaining a good body posture and balanced gait, we enable the induction of mechanical stimulations necessary for maintaining bone and muscle mass and at the same time, we don’t induce mechanical stimulation on the fat tissues.

People affected with long standing illnesses, the elderly, and people affected with certain types of injuries have one thing in common; along with reduced physical activity, their everyday activities do not provide the required level of strength and duration of mechanical stimulations necessary to maintain existing muscle, bone and fat mass.

On the one side, their condition restricts their physical activity and on the other side, by doing any physical activity, it forces them to maintain a high level of efficiency of supporting and carrying their body weight.

By observing the gait patterns and body posture of people affected with identical conditions, it can be noticed that they have a similar gait and body posture.

The level of strength and duration of mechanical stimulations on the body, produced by working against the pull of gravity to a greater extent, regulates the weight mechanism of the body and regulates food intake (and also water and air intake).

We can provide mechanical stimulations to the body even if we are not working directly against the pull of gravity, like when we consciously or unconsciously contract the muscles. In this way, we still provide some parts of the body with mechanical stimulations. On the other side, consciously or unconsciously contracting the muscles, the muscles are physically active but they do not work against the pull of gravity or against any other outside force like the force of friction etc. In this case, the muscles get bigger in size but not stronger (increased muscles mass without increased muscle strength).

Among the elderly, people with long standing illnesses, people affected with certain types of injuries and among people affected by weightlessness, a voluntary or forcible intake of any amount of food above the existing appetite will not cause weight gain, and will not even stop weight loss, and all food intake above the existing appetite, will be discarded by the body and expelled as metabolic waste.

For relatively healthy people, voluntary or forcible food intake above the existing appetite usually has the consequence of decreased efficiency of locomotion and decreased efficiency of supporting the body weight (in standing and sitting position) against the pull of gravity.

Decreased efficiency of locomotion is reflected in an unbalanced walking and running gait. A decreased efficiency of locomotion has the consequence of producing stronger impact forces when walking and running (walking and running is an act of transferring the body weight from one leg to the other). Stronger impact forces induce excessive mechanical stimulations to the fat, muscle, and bone tissue.

This is to conclude that besides air, water and food, two more factors are essential for maintaining life by humans, and those factors are mechanical stimulations and the use of bones and muscles.

  1. The use of the muscles and bones is the factor that maintains the existing strength and generates new body strength.
  2. Mechanical stimulations is the factor that maintains the existing and generates new bone mass, muscles mass and fat mass.

Our life depends on air, water, food, physical activity (the use of muscles and bones) and on mechanical stimulations produced mainly by working against the pull of the Earth’s gravity.

  1. The absence of mechanical stimulation on the muscle tissues, fat tissues and bone tissues caused by physical inactivity causes the process of atrophy.
  2. The absence of mechanical stimulation on the muscle, fat and bone tissues caused by an improvement in postural strength and motor skill causes the process of regression of excessive fat mass.

In some cases, only the bone tissues are affected by an insufficient induction of mechanical stimulations and in some cases, only the muscle tissue, and in some cases only the fat tissue.

The absence of mechanical stimulations will cause atrophy (regression) whether it is the bone, muscle or fat mass.


Prolonged hunger causes body weakness. Weakness causes a change of locomotion. With the presence of muscle weakness, we are mostly in a subconscious level increasing the efficiency of locomotion. The increase of the efficiency of locomotion is the factor that causes a decrease of strength of mechanical stimulations below the level required for maintaining body mass. This means that the body does not lose weight because of an absent or insufficient food intake, but because the absence or insufficient food intake among humans and animals changes the locomotion and body posture in a subconscious level, and that results in an increased efficiency of locomotion and increased efficiency of supporting the body weight. This has the consequence of decreased mechanical stimulations to the bone, muscle and fat tissue.


The absence or harsh restriction of food intake without a decrease of mechanical stimulations will not produce weight loss, but in a short time will lead to the loss of life.


By doing nearly any physical activity here on Earth, we work against the pull of the Earth’s gravity. In the first place, we have to support our own body weight against the pull of the Earth’s gravity.

Supporting and carrying our own body weight is the task where we put most effort throughout the day and at the same time, by supporting and carrying our own body weight we maintain the existing and in some cases we generate new postural strength, postural stability, the sense of balance, and the strength of the immune system.

The use of muscles and bones is the factor that maintains and improves the strength of the muscles and bones.

One kind of mechanical stimulation on the body is possible to produce without working against the pull of gravity, like by doing exercises in a weightless environment on a specially designed exercise machine, or by consciously or unconsciously contracting muscles, but this type of mechanical stimulations is not sufficient for maintaining the existing mass of the body, and it is meaningless for maintaining postural strength, postural stability and the optimal biological process in the body.

Effective maintenance and improvement of postural strength, postural stability, motor skill ability and immune system strength is possible only by working against the pull of the Earth’s gravity.

Concerning weight, shape and health, people should take attention of their gait, body posture, postural strength, postural stability, and motor skill.