Overweight Effects on Metabolic Rate, Chronic Diseases, Time Perception, Aging, and Lifespan: a Systematic Review

Background: The hypothesis that metabolic rate is inversely correlated with lifespan has long been debating. Another area of controversy is an evidence of a relationship between metabolic rate and time perception, and aging. Aim: to study the impact of overweight and food intake on metabolic rate, time-ow perception, chronic diseases, aging, lifespan; diculties in weight loss. Methods: Design: a systematic review. Setting and Participants: Web of Science, Scopus, Science Direct, Kopernio, PubMed, Mendeley were searched for articles published from January 1979 until March 2020. The study bases on a viewpoint supported by a systematic literature review of 3612 articles published worldwide. Results: In total, 107 full-text articles were assessed for eligibility. From them, 25 articles were excluded with reasons. Overweight and food intake are the main causes of accelerating metabolic rate. By age, the body should less calorie intake due to decreasing metabolic rate. Body capability to gain weight is integral indicator of body energy reserve that depletes after weight gain. Increased metabolic rate creates a delayed time-ow perception and accelerates aging. Metabolic rate and lifespan are inversely correlated. Weight loss is a good tool to delay aging and increase lifespan. Very-low-calorie diets and to manage metabolic intoxication should use at weight loss. Conclusions: The ndings support overweight with overeating increases metabolic rate that in turn delays time-ow perception, increases disease, accelerates aging, limits lifespan. For weight loss has to manage a very-low-calorie diet.


Introduction
The prevalence of overweight burden is increasing among population of all countries of the world.
Overweight has an adverse effect on health and lifespan. (1) The risk of chronic diseases incidence and mortality is rising in the last several decades despite better hygiene, modern detection technologies and discovery of antibiotics, subsequent 2-3 generations are sicker than previous generations at same age. (1,2) The hypothesis metabolic rate (MR) is inversely correlated with lifespan has been long debating. (3,4) MR increases to repair cellular damage using metabolic substrates. (5) MR inversely correlates with aging and lifespan. Physical activity, correlated with MR and estimated by mean walking speed, was positively correlated with mitochondrial DNA copy number. MR may increase to provide energy to repair a cellular damage. (6) Ambient temperature increasing in optimal range improves body fertility, but decreases body lifespan. (7) High MR across 46 species was associated with lower survival but other factors also in uence to survival and metabolism. (8) Many researchers discuss the idea that overweight may accelerate the rate of aging and shortening lifespan and health span. (9) Overweight is associated with excess mortality and greatly increased coronary artery disease incidence. (10) Another area of controversy is evidence of the relationships between overweight and MR, time-ow perception (TFP), aging, lifespan.
Humans have a psychological mechanism for perception of slowing time down as motion speeds up, (11) or every event and its repetition-expectations differentially affect the perception of time. (12) Considering how MR might in uence time perception helps reduce the existing gap between our understanding of physics and our understanding of human physiology.
Weight loss methods improve in multiple cardiovascular risk markers, reduce in medication, improve MR. (13,14) However, not every weight loss method can support metabolic health, reduce in energy expenditure, reduce oxidative damage, and delay age-associated declines in physiological function. (15) The impact of overweight on MR, health and diseases, aging and lifespan was separately investigated before, but all in conjunction was not studied, especially the impact of overweight and MR on TFP. The present review helps to ll in this gap that aim was to study the impact of overweight and food intake on MR, TFP, chronic diseases, aging, and lifespan; di culties in weight loss. The search strategy included only terms relating/ describing to the exposure/ intervention. To this topic devoted not so much literature worldwide, especially, to the association of overweight, perception of time passage, MR and gravitation (gravity), aging, lifespan. We searched the literature and recorded the search results. These records were screened and eligibility criteria applied, a smaller number of articles remained.

Methods
There were no language restrictions. The searches were re-run before nal analyses, and applicable further studies retrieved for inclusion. Two researchers independently assessed and then reached an agreement on the included studies and the extracted data. All types of studies were included.

Results And Discussion
In the initial search, 3612 relevant articles were identi ed. 208 records after duplicates were removed. After the titles, abstracts, and texts were evaluated, 1151 articles were excluded (Fig. 1). In total, 107 fulltext articles were assessed for eligibility. From them, 25 articles were excluded for the following reasons: twelve articles were excluded because they did not distinguish obesity from overweight; thirteen articles were excluded because they did not provide aging process and lifespan. Therefore, the nal sample comprised of 82 articles.
Body mass, Food intake, Metabolic rate Basal metabolic rate (BMR) represents 75-80% of a total daily energy expenditure, and only 20-25% of a total energy expenditure is used for external work as physical and mental activity. The largest part of BMR spends on food intake and digestion. On average, a 100-kcal surplus in daily energy expenditure and positive one percent shift in 24-hour respiratory quotient were associated with independent increases in ad libitum food intake of approximately 175 and 204 kcal/day, respectively, indicating that both the underlying metabolism and substrate oxidation are competing drives for food intake. (20) For each 100 kcal/day extra intake, the body expends ≈ 50 kcal/day from own reserve.
Daily extra food intake increases metabolic stress to the body. Excess food intake increases both BMR and active metabolism. (21) Over-metabolism consumes body "vital energy".
The body expends more energy on excess protein digestion, for instance, protein increases thermogenic effect up to 25% of total energy expenditure. (22) A protein diet speeds up MR. Protein metabolism loads all detoxi cation organs as kidneys, liver, skin, and lungs. A simple restriction of food intake decreases in MR by 45%. (23) The body on Earth needs to have muscle mass to overcome gravitation. Body fat also consumes the body energy. When the body doesn't need in muscle mass, it will hypotrophy as it takes place in open cosmos, (24) but the trend does not happen with fat mass. Fat mass does not atrophy in the body and it can live for many years.
Overweight, Metabolic rate, Gravitation, Time-ow perception According to both classical Newton's physics and quantum physics (Relativity theory), the body speed and time are inversely correlated. (25) Slowing time creates a delayed TFP. MR increases accordingly with increase of body speed. Consequently, with increase in MR the TFP slows down.
Gravitation also delays time ow (gravitational time dilation) (26) and directly proportional in uences body MR. (27) The stronger gravitation, the slower the TFP. MR is reduced by 19% at 'zero gravitation'. (28) Gravitation in uences on time-ow both directly and through effects on body MR. Gravitation boosts MR and slows TFP. (11) TFP is accelerated with human aging (29) also due to slowing MR down.
Human activity depends on metabolism, (30) therefore MR in uences on TFP.
Overweight accelerates MR. (31) Overweight people more often complain of fatigue and discomfort. Delayed TFP also occurs in people with overweight when they feel tired. The fatigue feeling may be associated with a decline of endurance threshold. (32) According to the Thermodynamic Second Law every desired result takes effort.
A delayed TFP is observed in people waiting some event, or engaged in unloved affair. (12) Obviously, 'waiting process' speeds MR up.
Delayed TFP is also observed in childhood (they have a fast MR), and accelerated TFP in old people (they have a slow MR). Increased MR delays TFP. Table 1 shows the summary result of studies assessing the impact of MR on TFP. While goes MR down a nutrient intake should be decreased accordingly. Nowadays, modern eating habit increases overweight prevalence.
Animal world also con rms the relationship between MR and TFP. The slower metabolism (cold-blooded animals) the more TFP accelerates. (30) In turtles (slow metabolism), time seems like "go fast", but in hummingbirds (fast metabolism), time seems like "go slowly". Nutrient intake should be optimized for energy eco-mode.
Overweight, Metabolic rate, Energy expenditure, Lifespan Weight, MR and body reserve are correlated to each other. The more weight, the more body maintains a higher MR. Increase in bodyweight and metabolic activity are accompanied by rapid body growth, but short lifespan. (40) Table 2 presents summary of studies in uence of a high MR on aging, survival and lifespan in humans and animals. Overfat gain is unfavorable process for body energy. Overweight increases the total pool metabolites. (42,45) Overweight reduces tolerance to physical/mental stress. (9) For each 100-kcal/day increase in energy expenditure, the mortality risk increases by 1.

Individual bodyweight, Potential body energy, Lifespan
To accumulate fat mass ability is one of the basis to survive at food de ciency. Food de ciency accompanied the humankind continuously. Currently, the survival ability leads to obesity-epidemic. (1,19) Every person has own individual bodyweight. Normal bodyweight is when the body does not suffer from any diseases. The more potential the body has, the more weight he can gain. Weightgain is limited due to body potential. Weight limit is when weight cannot increase, and when weight stables at the highest point of weightgain that is 'terminal bodyweight'. Bodyweight is an integral indicator of body energy.
Disease is an energy crisis signal. Each disease is accompanied by weight loss. (13,55) Weight loss helps to recover. Simple restriction of food intake decreases MR by 45%. (23) Decreasing MR is the saving body ability at food shortage.
Bodyweight tends to increase with age and it is only associated with fat gain. (10) The amount/stage of chronic diseases increase with age as well. (63) Various diseases is associated with individual chronobiorhythms. (2) Overweight is a consensus between body potential and nutrient reserve.

Aging, Metabolic rate, Weight loss
Effect of calorie restriction on aging and age-related diseases is well described. (

Declarations
Ethics approval and consent to participate. Not applicable Consent for publication. Our manuscript does not contain any individual person's data in any form. All authors of the manuscript a rm that they had access to the study data and reviewed and approved the nal manuscript.
Availability of supporting data. Not applicable.
Competing interest. The authors declare that they have no any competing interests ( nancial, professional, or personals) that are relevant to the manuscript. We have read and understood the journal policy on declaration of interests and have no interests to declare.
Funding: This research did not receive any funding from public, commercial, or not-for-pro t sectors.
Authors' contributions: KO: design and performance, narrative analysis and review, bibliography review, data collection, scienti c analysis, scienti c executor, writing, editing, and revision. GB: study design, writing the discussion, bibliography and paper review. MG: design and performance, scienti c analysis, bibliography and paper review. BD: preparation e-version data collection, bibliography and paper review, scienti c analysis, writing the methods. AT: scienti c analysis, paper scienti c review, writing the methods and print. ARS: study design, research executor, editing, and revision. PRISMAchecklist.doc