(I am putting this thread together to organize the posts on this topic. The first four posts are from 2017 and appeared elsewhere in this forum and the Lounge)
For those who follow my forum, here are a few links to some research that has been going on over the last few years (and decades) on activity/exercise called The Exercise Paradox. It has to do with how much exercise is enough and are much higher levels of exercise/activity the reason why ancestral and hunter-gatherers had an easier time avoiding excess weight and obesity. It also looks at the role our modern sedentary lifestyle plays in the weight equation reinforcing several points in this thread. I am working on a graphic representation of what all this is saying.
My original thread on exercise:
Exercise, Health & You: How Much Is Enough?viewtopic.php?f=22&t=43482In Health
Jeff
SCIENTIFIC AMERICAN
FEBRUARY 2017
The Exercise Paradox
https://www.scientificamerican.com/arti ... e-paradox/Studies of how the human engine burns calories help to explain why physical activity does little to control weight—and how our species acquired some of its most distinctive traits
(Unfortunately, this one is behind a pay wall. Here is a link to a recording of it and a PDF of it that is available for a short time)
https://us.ivoox.com/en/the-exercise-pa ... 909_1.htmlhttp://dropcanvas.com/1fcrcWhy do individuals not lose more weight from an exercise intervention at a defined dose? An energy balance analysis.
Obes Rev. 2012 Oct;13(10):835-47.
doi: 10.1111/j.1467-789X.2012.01012.x. Epub 2012 Jun 11.
https://www.ncbi.nlm.nih.gov/pubmed/22681398Abstract
Weight loss resulting from an exercise intervention tends to be lower than predicted. Modest weight loss can arise from an increase in energy intake, physiological reductions in resting energy expenditure, an increase in lean tissue or a decrease in non-exercise activity. Lower than expected, weight loss could also arise from weak and invalidated assumptions within predictive models. To investigate these causes, we systematically reviewed studies that monitored compliance to exercise prescriptions and measured exercise-induced change in body composition. Changed body energy stores were calculated to determine the deficit between total daily energy intake and energy expenditures. This information combined with available measurements was used to critically evaluate explanations for low exercise-induced weight loss. We conclude that the small magnitude of weight loss observed from the majority of evaluated exercise interventions is primarily due to low doses of prescribed exercise energy expenditures compounded by a concomitant increase in caloric intake.
Hunter-Gatherer Energetics and Human Obesity
Published: July 25, 2012
PLoS ONE 7(7): e40503.
http://dx.doi.org/10.1371/journal.pone.0040503http://journals.plos.org/plosone/articl ... ne.0040503Abstract
Western lifestyles differ markedly from those of our hunter-gatherer ancestors, and these differences in diet and activity level are often implicated in the global obesity pandemic. However, few physiological data for hunter-gatherer populations are available to test these models of obesity. In this study, we used the doubly-labeled water method to measure total daily energy expenditure (kCal/day) in Hadza hunter-gatherers to test whether foragers expend more energy each day than their Western counterparts. As expected, physical activity level, PAL, was greater among Hadza foragers than among Westerners. Nonetheless, average daily energy expenditure of traditional Hadza foragers was no different than that of Westerners after controlling for body size. The metabolic cost of walking (kcal kg−1 m−1) and resting (kcal kg−1 s−1) were also similar among Hadza and Western groups. The similarity in metabolic rates across a broad range of cultures challenges current models of obesity suggesting that Western lifestyles lead to decreased energy expenditure. We hypothesize that human daily energy expenditure may be an evolved physiological trait largely independent of cultural differences
Relation between Caloric Intake, Body Weight, and Physical Work
STUDIES IN AN INDUSTRIAL MALE POPULATION IN WEST BENGAL
Am J Clin Nutr
March 1956
vol. 4 no. 2 169-175
http://ajcn.nutrition.org/content/4/2/169.abstractThe relation between caloric intake, body weight, and physical work was established in a group of 213 mill workers in West Bengal. These workers covered a wide range of physical activity, from sedentary to very hard work. It was found that caloric intake increases with activity only within a certain zone ("normal activity"). Below that range ("sedentary zone") a decrease in activity is not followed by a decrease in food intake but, on the contrary, by an increase. Body weight is also increased in that zone. The picture is similar to that previously found in experimental animals.
Popular Press Articles
Why Physical Activity Does Little to Control Weight
SkepDoc's Corner
February 16, 2017
http://www.csicop.org/specialarticles/s ... rol_weightDebunking the Hunter-Gatherer Workout
NY TImes
August 24, 2012
https://mobile.nytimes.com/2012/08/26/o ... rkout.htmlDieting vs. Exercise for Weight Loss
NY Times
August 1, 2012
https://mobile.nytimes.com/blogs/well/2 ... /?referer=