Low physical activity levels of modern Homo sapiens among free-ranging mammals

Hayes, Matthew R.; Chustek, M; Heshka, Stanley; Wang, Z; Pietrobelli, Angelo; Heymsfield, S. B.

doi:10.1038/sj.ijo.0802842

Cited by 48 publications

(46 citation statements)

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“…59 Our analysis of human energy demands relative to those of wild mammals is discrepant with a previous comparison that concluded humans have lower energy demands than expected. 32 The reason for this discrepancy is because the previous study compared PAL values between humans and other species, but did not account for the effects of body mass on PAL. PAL values are calculated using the resting energy at thermoneutral conditions (BEE) under the assumption that the remaining energy demand predominantly fuels activity.…”

Section: Discussionmentioning

confidence: 98%

“…If modifications to our environment that reduced our energy demands precede the 1980s, and are not well reflected by the third world populations then we should be able to pick this up by reductions in our demands relative to that expected for equivalent-sized wild mammals as suggested previously. 32 The fourth source of information we analysed therefore was for all the published data on wild terrestrial mammals using the DLW method. Although the DLW method was invented during the 1950s work on wild mammals did not start until the 1970s.…”

Section: Methodsmentioning

confidence: 99%

“…29 The PAL normally varies between 1.5 and 2.0. 30,31 The PAL of modern humans has been previously compared with that of wild mammals, 32 and on that basis it was suggested that modern humans have lower than expected energy expenditure on activity and hence that lowactivity energy expenditure has fuelled the obesity epidemic. However, this latter study failed to adequately account for body size effects and the effects of ambient temperature on energy demands, a point we shall address in the current paper.…”

Section: Introductionmentioning

confidence: 99%

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Physical activity energy expenditure has not declined since the 1980s and matches energy expenditures of wild mammals

2008

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Objective: Obesity results from protracted energy imbalance. Whether this comprises excessive energy intake, lowered physical activity or both, remains disputed. Design: Physical activity energy expenditure, evaluated in three different ways from daily energy expenditure (DEE) measured using doubly labelled water, was examined for trends over time. Data included subjects in Europe (Maastricht, the Netherlands) and North America extending back to the 1980s. These data were compared with measures from the third world, and measures made on wild terrestrial mammals. Results: Physical activity expenditure in Europe (residual of the regression of DEE on basal energy expenditure (BEE)) has slightly but significantly increased since the 1980s. There was no trend over time in physical activity level (PAL ¼ DEE/BEE), or in the residual variance in DEE once mass, sex and age were accounted for. This latter index of physical activity expenditure also significantly increased over time in North America. DEE of individuals in Europe and North America was not significantly different from individuals measured in the third world. In wild terrestrial mammals, DEE mostly depended on body mass and ambient temperature. Predicted DEE for a 78 kg mammal living at 20 1C was 9.2 MJ per day (95% CI: 7.9-12.9 MJ per day), not significantly different from the measured DEE of modern humans (around 10.2-12.6 MJ per day). Conclusion: As physical activity expenditure has not declined over the same period that obesity rates have increased dramatically, and daily energy expenditure of modern man is in line with energy expenditure in wild mammals, it is unlikely that decreased expenditure has fuelled the obesity epidemic.

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Section: Discussionmentioning

confidence: 98%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Physical activity energy expenditure has not declined since the 1980s and matches energy expenditures of wild mammals

2008

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“…11,23 Modulation of NEAT appears to be important in weight gain, but more importantly individuals with obesity show low NEAT. Specifically, obese individuals have an innate predisposition to be seated for 2.5 hours per day more than sedentary lean counterparts.…”

Section: Neat In Weight Gain and Obesitymentioning

confidence: 99%

Non-Exercise Activity Thermogenesis

Levine

Weg

Hill

et al. 2006

ATVB

191

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Abstract-Non-exercise activity thermogenesis (NEAT) is the energy expenditure of all physical activities other than volitional sporting-like exercise. NEAT includes all the activities that render us vibrant, unique, and independent beings such as working, playing, and dancing. Because people of the same weight have markedly variable activity levels, it is not surprising that NEAT varies substantially between people by up to 2000 kcal per day. Evidence suggests that low NEAT may occur in obesity but in a very specific fashion. Obese individuals appear to exhibit an innate tendency to be seated for 2.5 hours per day more than sedentary lean counterparts. If obese individuals were to adopt the lean "NEAT-o-type," they could potentially expend an additional 350 kcal per day. Obesity was rare a century ago and the human genotype has not changed over that time. Thus, the obesity epidemic may reflect the emergence of a chair-enticing environment to which those with an innate tendency to sit, did so, and became obese. To reverse obesity, we need to develop individual strategies to promote standing and ambulating time by 2.5 hours per day and also re-engineer our work, school, and home environments to render active living the option of choice. Key Words: non-exercise activity thermogenesis Ⅲ physical activity Ⅲ energy expenditure Ⅲ obesity Ⅲ malnutrition T he first law of thermodynamics is the thermodynamic expression of the principle of the conservation of energy and states that when energy is added to a system, it is either stored or used to perform work. Applying this physical law to living entities, such as animals, provides us with the conclusion that when total energy intake is greater than energy expenditure, excess energy will be stored as body fat. The physiological states of overweight and obese are a consequence of cumulative excesses in caloric intake.A pandemic of obesity has spread from the US to Europe and is now emerging in middle and even low-income countries. 1 Overweight and obesity are preventable causes of death and many comorbidities including type II diabetes, hypertension, stroke, cholelithiasis, degenerative arthritis, sleep apnea, and cancer. 1 With the prevalence of overweight and obesity increasing, the urgency to understand why humans are gaining weight has intensified.Understanding the specific details of this pandemic is important. Most articles reporting the rise in prevalence of overweight and obesity use body mass index cutpoints; all have reported striking increases in prevalence. Far more profound, however, is the changes in average heights and weights across all ages. 2 For example, since the 1970s, whereas the average height of American men and women has increased, the average weight has increased 25 pounds. It is tempting to attribute the increase in average weight to changes in population demographics, ie, "middle age spread," from aging baby boomers. However, no category of individuals has escaped without weight gain, as reflected in the trend of mean weight for both men and women...

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“…In addition to ensuring proper nutrition, the lifestyle associated with hunting/gathering activities is generally associated with increased fitness due to an increase in daily energy expenditure. Hayes et al 58 estimated that the highly active lifestyle of the ancient hunter-gatherers tripled daily energy expenditure when compared with sedentary adult humans living in industrialized countries. Yet, today, hunting/gathering techniques have greatly improved owing to the increased access to engine-driven transportation and modern cooking methods.…”

Section: Benefitsmentioning

confidence: 99%

Obesity and type 2 diabetes in Northern Canada's remote First Nations communities: the dietary dilemma

et al. 2010

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First Nations populations in Northwestern Ontario have undergone profound dietary and lifestyle transformations in less than 50 years, which have contributed to the alarming rise in obesity and obesity-related diseases, in particular type 2 diabetes mellitus. Even though the genetic background of First Nations peoples differs from that of the Caucasians, genetics alone cannot explain such a high prevalence in obesity and type 2 diabetes. Modifications in lifestyle and diet are major contributors for the high prevalence of chronic diseases. What remains constant in the literature is the persistent view that locally harvested and prepared foods are of tremendous value to First Nations peoples providing important health and cultural benefits that are increasingly being undermined by westernbased food habits. However, the complexities of maintaining a traditional diet require a multifaceted approach, which acknowledges the relationship between benefits, risks and viability that cannot be achieved using purely conventional medical and biological approaches. This brief review explores the biological predispositions and potential environmental factors that contribute to the development of the high incidence of obesity and obesity-related diseases in First Nations communities in Northern Canada. It also highlights some of the complexities of establishing exact physiological causes and providing effective solutions.

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Low physical activity levels of modern Homo sapiens among free-ranging mammals

Cited by 48 publications

References 10 publications

Physical activity energy expenditure has not declined since the 1980s and matches energy expenditures of wild mammals

Physical activity energy expenditure has not declined since the 1980s and matches energy expenditures of wild mammals

Non-Exercise Activity Thermogenesis

Obesity and type 2 diabetes in Northern Canada's remote First Nations communities: the dietary dilemma

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