Hunter/gatherer/farmer children bmr
https://www.sciencedaily.com/releas...91218153543.htm
https://advances.sciencemag.org/content/5/12/eaax1065 Okay--I included a sciencedaily link because that's where I got to the study itself from. But I found the article goofy and less succint than the abstract, so that's what I'm copy/pasting here.... Quote:
Increased metabolic rate due to increased immune activity is interesting--obvious implications/avenues to look at when it comes to the gut biome, immune activity and energy expenditure. If you wander around looking at leptin studies, a bit of reference jumping gets you to interactions with the immune system fairly quickly. The physical activity bit is interesting as well. Assuming that first bit was interesting. :lol: Quote:
Wall of text--Shuar children have total energy expenditure comparable to the more industrialized children they're compared to here. But resting energy expenditure is higher, and they're also more physically active. T Nation has a lot of articles suggesting mixing up endurance exercise--as we get better at an exercise, we do it more efficiently--burn less calories. Stay inept to burn more calories. So Shuar children are more efficient, and have less mass to move about--so they burn less calories when active. What I didn't like about the sciencedaily article. The summary wasn't so bad; Quote:
Leaves room for subtleties. There might be something about how they spend their calories, about the metabolic activity going on, that contributes to their different, less fat phenotype. Or you could just read the headline; Quote:
And here; Quote:
Better than the headline--but still. Immune system burned more calories? Why didn't the children just have larger appetites, and eat to make up for it? Or were they hungry all the time, and not eating to appetite? Saying, well, resting energy expenditure goes down in industrialized children--but it's made up for by increased physical exercise energy expenditure in the face of reduced activity--well, I don't know. Couldn't you as easily say that the children eat more, but that's made up for by increases in energy expenditure during activity--and instead ascribe the increased body weight to the decrease in basal metabolism? Or stated another way--maybe US children eat more, but if it weren't for the decrease in metabolic rate, at least relative to the Shuar children, this wouldn't be causing obesity. After all this, I do think it's likely the food. :lol: But sheer available calories is a vast oversimplification. |
Who are the Shuar of the Amazon? Just reading about their food intake and calorie expenditure does not place this study in context for me.
What exactly is meant by "Forager-horticulturalist" and what percentage of time is devoted to each? This study provides less detail on food and calorie consumption that the early studies of the Masai in Africa who were completely dependent upon their cattle as their food source. Thanks for posting this study - it leave me with more questions than answers. |
The study does give some numbers--how many meals per week have fish, foraged, hunted, or shopped (some carby foods from town) items in them. Garden crops are given as the most common food item. I think a rough idea of calories is had from labeled water studies mentioned. These are growing children, so hopefully they're not in some sort of calorie surplus, but growth is slow enough that in non-obese children calories burned should at least give a rough sort of idea of what's eaten over time--the two should very roughly match.
For time spent hunting fishing etc. that's given as number of days per week where the activity occurs, but I don't see it broken into hours. The author says he's spent 25 months with these people since 2011. There I ask, which months? Earlier Inuit studies tended to be in the summer, for obvious reasons. The most convenient times of the year might not give the full story. Some peoples are seasonally fatter and leaner over the course of the year, this would have some effect on both bmr and energy burned during exercise, if you look at some of Rudy Leibel's leptin studies. For that matter I imagine North American children might measure a bit different during and after plum pudding season. |
So they are not an isolated tribe living in a forest environment. They live near a town. Do both boys and girls hunt and fish - or only boys. In my experience, there is a clear division of labor by gender.
Anthropologists do live with the Inuit in the far north for months - not just during the summer which is about 2 months. Otherwise how would they know the diets was primarily blubber during the winter. |
The girls are likely to fill the horticulurist title...gardening or collecting vegetation, fruit, and nuts is as physically difficult as hunting. And the girls are likely to give a hand in prepping and cooking the meat.
Proocuring your own food and cooking it requires must physical energy. |
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I said earlier studies--I'm talking the 20's. They still would know from anecdotes. Also I'm talking from the sort of medical literature I've seen from the time, I don't deny the work of people like Steffanson who lived among them, sometimes through all seasons. I had more in mind studies where blood and urine samples were take, ketones and blood glucose etc. analyzed. Anyways, just conjecture when applied to the Shuar, not something I'd assume to be true, but a question to be asked. |
Remember - medical literature is peer reviewed.
Not all reviewers are dispassionate - they makes decisions based upon their biases, not necessarily the science - note all the low carb researchers who complain about not getting published because their work does not fit the mainstream. Better resources for indigenous diet would come from anthropologists who have no ax to grind on diet. Especially in the early days when anthropologists actually went out in the field and lived with their research subject for years before publishing |
I was just making a point about field observation of diet and bmr being season sensitive. Not a criticism about the general usefulness of medical literature versus anthropology.
In this case, I was talking about bmr and the possibility that if their calorie intake or body weight fluctuates seasonally, whether they're in the fat or the lean season might have an effect on their bmr. |
No way to know, is there Teaser.
Doubt seriously that anyone has studied that particular question in any field. Especially in the '20s |
Today's Inuit, in the far north, as you know Teaser, are more likely to live in towns - especially during the winter - going out to hunt periodically - but mostly eating the food from the local store which is pretty high carb.
During the summer months, they go out on the land to hunt, fish and gather vegetation. I would assume that they would lose weight in the summer switching back to a purely low carb diet. Makes for a yo yo diet existence. The doctoral dissertation of Dr Nancy Edgecombe may have more information for you. Since she is the nurse in charge of Inuit health, she might be able to answer your question. She is on facebook if you have access to that platform. |
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