Sana Hospital Group 11 Mar 2021

Obesity has been recently reclassified as a preventable disease, highlighting the fact that the condition is a major risk to one’s health. During the current pandemic, obesity came to the fore of health concern once more as statistics report a higher number of obese individuals contracting COVID-19, versus healthy and underweight counterparts.

These observations have us wondering about excessive weight gain; what it does to the body and why it increases the risk of contracting an infection like COVID. The below discussion takes a look at the bodily changes associated with obesity, why it poses serious health risks, how it’s not just about working off calories and what one could do to potentially prevent it.

Why is Excess Weight a Problem?

Excess fat is not so much the issue as is compromised fat metabolism. Excessive fat can come and go at different stages of one’s life, such as during infancy, puberty, menstruation and in old-age.

If one gains weight and then finds that they battle to lose it, then excessive fat becomes a problem over time. In this instance, weight that cannot be worked off is also likely a symptom of a deeper health concern pertaining to cellular metabolism. In time, being unable to lose weight can cause obesity, which is a rather serious health condition. Obesity affects all aspects of health and places an increased burden on many systems of the body. This is largely due to the way in which excessive fat modifies the shape of nearby tissues and structures, such as blood vessels.

The placement of fat and its distribution also play a role in determining how harmful excess weight is for health. Increased abdominal fat, particularly around the waist, is often associated with cardio and digestive problems. If the fat is not distributed evenly in a sex-appropriate phenotype, it is also not a good sign and can increase obesity-associated mortality significantly.[1]

Furthermore, fat cells are not exactly inactive themselves and exert biological effects just like all other cells in the body. In excess, the action of fat cells can be deleterious to the way in which the rest of the body functions.

Health Risks Associated with Obesity

Obesity increases the risk for all-cause mortality and for acquiring the majority of chronic lifestyle diseases[2]. Specifically, obesity is associated with metabolic disorders, cardiovascular abnormalities, respiratory issues[3], weaker bones and hormonal imbalances[4].

The main metabolic disease that obesity increases the risk of acquiring would be diabetes, however there is a big association with obese individuals and all-round metabolic syndrome as well.

In cardiovascular studies concerning obesity, it has been linked with increased survival after heart failure. In spite of this, it also increases the risk of heart failure due to being associated with stiff arteries and other vascular abnormalities that increase resistance and therefore decrease blood flow.

It was observed that obese patients had a significantly higher risk of pulmonary hypertension or increased blood pressure within pulmonary circulation[5]. This largely correlates with both the vascular alterations and respiratory changes that obesity often induces. Lung function is often compromised in obese individuals, particularly the lower portion of the lungs[6]. Not surprisingly, obesity is associated with impaired breathing, increased asthma risk, as well as a higher incidence of snoring and sleep apnea.

Some studies have shown that generic bone marrow stem cells in the body can choose to become either fat, bone or muscle tissue. In obese people, it is often the case that this process of stem cell differentiation favors fat turnover instead of bone or muscle, which means that bone and muscle tissues may begin to shrink without sustained turnover.

Fat cells promote the release of inflammation and can cause chronic low-grade inflammation, resulting in an increased risk of disease, particularly diabetes.[7]

Lastly, fat cells have been shown to be highly involved in the production of estrogens in both men and women[8]. When there is too much fat, estrogen can become overproduced. Estrogen regulates fat production in both men and women[9], however testosterone regulates fat production in men as well[10]. Unbalanced hormonal ratios in both genders can contribute towards obesity, with outcomes generally being worse for men on the hormonal front due to the estrogen-heavy nature associated with fat. [11]

Obesity as a Major Cause for COVID-19 Concern

As one might imagine, the increased pressure on the lungs places obese individuals at a higher risk for mortality with regards to COVID-19 and other pernicious respiratory tract infections. Statistics over the last year have only highlighted the need for obese people to take extra precautions and to look after their health. Of those that needed hospitalization, ventilation or who suffered from COVID-related complications, many were obese[12] [13].

Obesity is also linked with having an under-functioning immune system, characterized by chronic low-grade inflammation. Due to the hyper-inflammatory nature of COVID-19 and its deleterious effects on immune function, outcomes are not promising for those who bear excessive weight - a plausible theory that is reflected through recent statistics.

In light of this information, obese individuals are being encouraged to make healthier lifestyle choices to improve their health in order to prevent the spread of the disease. However, making simple lifestyle changes, such as increasing physical activity, may not promote weight loss for many with obesity and therefore such encouragement (and criticism) is often inappropriate. 

Why Weight Loss is Not Always as Simple as Calorie Control

There is a very vague understanding in the general population about how to maintain optimal weight. We’ve all been told to exercise regularly and keep calories to a minimum in order to balance our energy expenditure and keep a healthy body mass index (BMI). This view is incredibly dated and is simply too simplistic a picture that ignores the truth for many who are faced with obesity. It is also often coupled with a nasty critique of obese people, implying that they are lazy, eat too much, and lack self-control – the height of which has created fat-phobia in many people.

Obesity was first shamed in this way, becoming stigmatized. One of the main issues with the above attitude is that it firstly ignores the severity of the condition while secondly blaming the person with the condition for not trying hard enough. It should be acknowledged that obesity is a serious health concern and that the causes for the condition are multifactorial and mysterious, as is the case with many chronic lifestyle illnesses. Nobody would blame someone with cancer or diabetes for not trying hard enough; it simply would not be fair on the person. The same can be said of anorexic individuals or even healthy individuals who suffer symptoms from time to time.

In the last few decades, a lot has come to light about obesity that puts these old-fashioned sentiments into retirement, including research that delves into the deeper causes of this health condition.

The Anti-Exercise Hypothesis: Are Humans Evolved to Frequent the Gym?

It’s true that leading a sedentary lifestyle is a risk factor for obesity and for just about all other common lifestyle diseases. This has led to the need to incorporate physical activity in order to counteract the effects of modern living, such as going for a daily jog around the block or frequenting the gym. However, many modern methods for exercising are likely to conflict with the ways in which the human body has adapted to engage in physical activity. Professor Daniel Lieberman, a Paleoanthropologist and Professor in the Department of Human Evolutionary Biology at Harvard University recognized for his research on the evolution of the human head and body, is currently exploring this hypothesis and makes a few relevant points that bust modern myths about exercise.

He points out that anthropological studies on the ways in which modern day hunter-gatherers engage in physical activity is not too different to our own. On average, they spend 2.25hours being physically active and the remaining 10 hours of their day is often spent sitting. Lieberman emphasizes that physical movement was only done when necessary or socially rewarding. Hunter-gatherers hunted and foraged out of necessity, but also would get active for the sake of social fun, such as dancing, participating in sports or playing games[14]. He hypothesizes from this that humans were not evolved to avoid sitting in order to be healthy or that excessive sessions at the gym could somehow compensate for natural movement.

Modern day gym gadgets, such as treadmills and other equipment, are frequently associated with injury, as is over-repetition and over-exertion. The latter is also frequently associated with dehydration, muscle cramps and stiffness, increased bodily stress, chemical release and overall, a peak in inflammation. By contrast, sports, games, physical hobbies and movement-oriented social events are less often associated with over-exertion and are usually far more enjoyable. Lieberman elaborates on this point by highlighting the myth that aging necessitates that people refrain from participating in enjoyable physical activity that can be beneficial.

Some facts that people should realize about burning fat and building muscle is that it is a process of increased energy metabolism, increased cellular destruction and increased cellular growth. This is why incorporating regular physical activity into one’s life is important, as well as why it could be detrimental if not balanced. Having an under-functioning immune system or lacking the nutritional resources to manage the exertion is more likely to contribute towards an unhealthy weight profile via increasing inflammation. In this respect, binge exercising or overexertion are as unhealthy as not exercising at all.

Challenging the Concept of Calories

The rate at which one can exert oneself is proportional to energy metabolism, but energy metabolism is not only related to calorie intake. Calorie intake is a very small consideration within the vast pool of factors that affect cellular metabolism.

Cellular energy metabolism is so complex that it has taken decades for us to begin to understand the basic mechanisms that drive it at the cellular level. Research into mitochondria, the powerhouse of the cell, has revealed that energy metabolism is governed by the fine chemistry of oxidation, also known as the redox balance. [15]

The mitochondria are processing multiple molecules to produce energy, some of which are highly reactive and volatile substances. Their efficiency is maintained through the use of antioxidants and cellular co-factors which keep oxidation balanced within the cell.

Damage or mitochondrial stress can result in unbalanced chemistry that leads to increased cellular toxicity in the form of excessive free radicals. However oxidation is not the issue, unless it becomes too high or too low and is very much a requirement for the function of all cells. Different parts of the cell respond to various oxidation states and in this way, the cell’s metabolic profile can be assessed.

Naturally this entire process is complex (Krebb’s Cycle) and can be altered at any step of the way by inter and intracellular compounds and chemical interactions. In this way, energy metabolism conveys countless unique molecular profiles and thus it is not a simple matter of calories.

Obese individuals have been noted to have a metabolism different to those who don’t battle to lose weight, in that they suffer from a unique form of mitochondrial dysfunction[16]. The reason behind this can vary from person to person. Studies conducted in populations with different genetics highlight this variance, revealing that some people gain weight by doing more and consuming less while others gain weight by doing less and consuming more[17].

Potential Causes of Obesity

As previously mentioned, obesity can be caused by many factors that often have little to do with calorie intake and energy output. Obesity has far more to do with one’s energy balance over time than with how much energy one expends relative to the calories one consumes. It has been proven that obese people expend as much energy as healthy and underweight individuals and that the resting state itself demands a substantial portion of our energy. Obesity is thus an energy metabolism problem.[18]

There are many factors that can influence energy metabolism, including genetics, microbiome, diet, lifestyle and phase of life.[19]

A currently promising hypothesis for obesity is one of gut dysbiosis[20], leading to shifts in metabolism that result in impaired fat metabolism. Gut bacteria are known to regulate many aspects of our physiology, particularly with regard to nutrient absorption and metabolism[21]. Much of the high calorie foods we associate with getting fat are altering the microbiome in such a way that promotes weight gain.

Increased levels of toxicity may also be a cause of excessive weight gain. If elimination pathways in the body are impaired, the excess toxins may be stored in the form of fat. Gut dysbiosis is likewise a factor that can increase systemic toxicity.

Thyroid issues are known to promote obesity[22]. The thyroid and parathyroid glands are highly involved in regulating the body’s calcium balance. Calcium is a huge electrolyte involved in mitochondrial energy production and so it is not surprising that an issue with calcium metabolism may lead to weight gain.

In the same way, certain nutritional deficiencies have been associated with specific types of weight gain, not common to most obese individuals. These include Beri-Beri and Kwashiorkor diseases.

Lastly, predisposing genetics and conditions associated with autoimmunity, endocrine disruption or brain inflammation could also cause shifts in metabolism that may contribute toward obesity.

7 Tips for Promoting a Balanced Weight Profile

For some, excessive weight can be easily controlled, while for others, it amounts to a deeper problem with metabolism. If you’re having serious trouble losing weight, it is far wiser to seek professional help than it is to attempt risky diets or rigorous weight loss programs that do not address the underlying cause.

In the meantime, leading a healthy lifestyle can’t hurt! The following 7 tips are not likely to reverse obesity, but may help to improve overall metabolism which is conducive to maintaining a balanced weight.

1. Eat Well

Here is where it all goes wrong for those trying to lose weight. Every decade there is some new health fad telling us what ‘eating well’ means and why the previous decade’s wisdom is misleading. Every major food group has been overly scrutinized with an argument for and against why one should consume more or less of each. Yet, with each decade, the incidence of lifestyle diseases has increased.

The hallmark of the research that defines these highly biased dietary trends, such as ignoring all fat or cutting out all salt, is that anything in excess is an issue; not that the entirety of that food group is an issue. Extreme interpretations of the results have led to health fads that are far more harmful than they are healthy. The diet should be varied and contain all nutrients in the right proportions. One’s lifestyle and environment influence this quite dramatically, making it difficult to design a diet plan for the human race as a whole. The definition of eating well is therefore going to differ from place to place, culture to culture, and person to person.

Nevertheless a few dietary trends appear common to all humans with regard to being healthy. These include:

  • Eating a diet high in water-soluble fiber
  • Consuming adequate minerals, vitamins and other essential nutrients
  • Including balanced amounts of probiotic foods in the diet
  • Avoiding a diet consisting solely of processed foods that lack nutritional substance

More often than not, the above aspects point towards consuming a colorful diet consisting largely of fresh fruit and vegetables, with moderate portions of fat, salt, sugar and protein. The best forms of all of these types of food will differ depending on your genetics.

Those who live in harsh conditions or who lead very active lifestyles tend to consume larger amounts of protein, fats and other nutrients to sustain their metabolism under these conditions. In any other setting, doing so can lead to metabolic issues. Cultural dietary practices tended to have evolved to cater for the needs of those living in the specific region the practices originated from. The Western world has done a great deal to standardize diet for everyone, which has likely interfered with natural dietary habits, variability of food and adaptations to local environments.

2. Focus on Improving Gut Health

Maintaining a diversity of healthy gut bacteria ensures that food gets digested properly and that all nutrients are absorbed efficiently. Furthermore, it keeps the gut happy and healthy, lowering the risk of an immune breach, micro-punctures in the gut lining and absorbing too many gut toxins. The gut microbiome regulates many aspects of our overall health, including the way in which fat is processed. Many good gut bacteria also release healthy fats that regulate fat metabolism.

Fecal samples from obese individuals reveal a common trend in microbial loss of diversity, coupled with an decrease in bacteria from the phyla bacteroides and an increase in firmicutes[23]. Where there is a loss of bacterial diversity, one often sees a rise in one or just a few specific types of bacteria. Even if that bacteria is healthy for you, it is not healthy in excess. Including a large variety of probiotic foods as well as fiber-rich substrates for them to thrive upon will help to reinstate bacterial biodiversity.

3. Stay Hydrated

Drinking enough water ensures proper elimination and excretion, healthy digestion and enhanced cellular metabolism, as water is a rich source of oxygen and a few vital trace minerals. Fiber and probiotics require water in order to function in the desired way and improve the health of the gut.

4. Find What Gets You Moving

Consistent physical movement is a component of correcting the gut microbiome, having a positive effect on bacterial populations that maintain a healthy metabolism[24] [25]. It is also important for adequate elimination and recycling of fluids in the body.

The best forms of exercise are never forced, rather being there as a natural source of enjoyment. Studies have proved that some people are naturally more energetic than others, even when healthy and will naturally go on to do more physical activity than others. The only constant from person to person is that rest and movement need to be varied. If you overdo one or the other, your metabolism will suffer and you will likely feel the impact.

However, daily movement need not be excessive. If weight is lost too rapidly, it can be associated with other side effects such as heart arrhythmias, electrolyte imbalances and stretch marks.

As highlighted above, our ancestors were likely to have led a surprisingly sedentary lifestyle that included necessary or socially rewarding forms of movement. Turning movement into a social event and doing it with friends can help to improve one’s motivation in a way that perfectly coincides with evolution.

In today’s pandemic, physical movement is important for retaining our health and well-being, as is social contact. There are many enjoyable forms of movement in which social distancing can still be maintained. Online exercise groups offer another option where lockdown restrictions are particularly strict.

5. Rest Properly

Rest is as important as movement to the gut microbiome[26], bodily elimination and other factors affecting energy metabolism.

Bacteria and cells alike respond to our circadian rhythms by syncing the production of various compounds in time with it[27] [28]. Setting a healthy rhythm helps overall metabolism and an out-of-sync rhythm (e.g. insomnia) is associated with weight problems, amongst other things.

Getting to bed at the right time and deep sleep for around 8hours a night helps to regulate metabolism[29]. One’s circadian rhythm is largely set during childhood[30], with that rhythm still being the best one for health later on in life. Most people appear to benefit from falling asleep sometime before 11pm and any time after 8pm. The time and length of sleep also changes depending on energy expenditure. One might sleep more or less in the event of having certain genes, illness, physical growth or fatigue due to increased activity.[31]

Rest also consists of resting the mind. Many forms of perceived inactivity can be just as draining as perceived activity. For instance, working in office conditions is a sedentary activity that can use just as much energy as an activity that involves much physical effort. Furthermore, physical movement generates energy in the process, whereas being sedentary does not, meaning that sedentary activity can cause higher energy expenditure in some cases than physical activity.

In this regard, many people often do not rest enough for the energy they expend. Resting is very much linked with breathing and minimizing activity, including brain activity in response to electronic devices. When you rest, rest fully in order to keep your energy metabolism balanced. Take breaks from all forms of stimulation (including artificial light, sound, etc) during rest and particularly in the last hour before sleep in order to maximize the benefit.

6. Breathe

The two things that both exercise and rest have in common would be breathing. When done correctly, both cause our breathing to become deeper and enhance overall circulation around the body. Breathing is a direct way in which we can promote the health of the cardiovascular system without posing any negative side effects; or worrying if we are under or over doing it.

Indeed, studies reflect that simply taking the time to inhale as deeply as you can and exhaling as much as you can a few times can dramatically improve blood flow, even in those with obesity.[32] The improvements were associated with lowering of activity in the sympathetic nervous system which improved metabolic outcomes in those with obesity.

7. Avoid Anything That Might Disrupt Hormonal Health

Adrenal, reproductive, digestive and thyroid hormones are all closely linked and have the tendency of feeding into one another. A deficit in one tends to cause hormonal problems all across the board. For instance, high adrenal activity and increased corticoid levels tend to be associated with higher inflammation, sex hormone ratio imbalances, and increased insulin resistance, particularly if allowed to persist through time.

By minimizing factors that negatively affect hormonal health, balanced energy metabolism is easier to maintain.

Due to their wide associations with many systems of the body, hormones are easily disrupted by many of the above factors when out of balance for a long time. Hormones can additionally be affected by the following:

  • Chronic stress
  • Lack of sunlight exposure
  • Chemical agents
  • Excessive exposure to plastic compounds[33]
  • Overuse of various pharmaceutical drugs
  • Overconsumption of potent hormone-modulating foods
  • Excessive alcohol consumption
  • Nutritional deficiencies


The incidence of obesity has seen an alarming rise in the last few decades in spite of the many health trends and attempts to prevent its occurrence.

Recent evidence highlights that energy expenditure is more complicated at the cellular level than previously thought, revealing that obesity is brought about by a chronically unbalanced cellular energy metabolism. Several factors impact cellular energy metabolism including diet, lifestyle, hormones, genetics, and the state of the gut microbiome.

By maintaining a balanced lifestyle consisting of both rest and physical activity, as well as ensuring a varied nutritious diet that supports gut health, one stands the best chance of preventing obesity. Prevention measures may not be enough to avoid obesity in those with genetic susceptibility or other chronic conditions.

If you are suffering from obesity, the best thing to do is to get professional help.

About the Author:

Sana Hospital Group is one of the largest independent healthcare providers in Germany. With over 50 world-class hospitals and more than 2 million patients yearly, Sana operates leading facilities, among them university hospitals, tertiary care centers, and specialized hospitals to deliver a broad portfolio of top-tier medical care. Whether it is preventive health care, an acute or chronic illness, a planned procedure, or a long-term diagnosis - more than 600 chief physicians, 4,500 medical professionals, and 11,000 nursing staff provide excellent treatment options, world-class medicine, and the best possible medical care.


  • [1]
  • [2]
  • [3]
  • [4]
  • [5]
  • [6]
  • [7]
  • [8]
  • [9]
  • [10]
  • [11]
  • [12]
  • [13]
  • [14]
  • [15]
  • [16]
  • [17]
  • [18]
  • [19]
  • [20]
  • [21]
  • [22]
  • [23]
  • [24]
  • [25]
  • [26]
  • [27]
  • [28]
  • [29]
  • [30]
  • [31]
  • [32]
  • [33]

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