Why humans crave fatty foods
Discussion
mattikake said:
A good read, but I can't say I fully agree. Ignoring the fact that many things in human biology are not fully understood and still under great debate, the human digestive system is equally well equiped to process carbs as well as fat. And we do crave carbs in the form of sugars, just as much as fat.
While we have 3 types of fat digesting enzymes (1 in mouth, 1 in stomach, 1 in pancreas/dudodenum) and 2 types of carb digesting enzymes (1 in mouth, 1 in pancreas/dudedenum), we can actually breakdown and absorb carbs about twice as fast as we can fat. Fat has to go through an emulsification process, that is time consuming and complex, whereas carbs don't.
The part at which the article speaks of losing our need to crave carbs being evident from our less complex guts, is misleading. Complex guts are there to digest cellulose (plant matter) not carbs - or rather carbs from cellulose. But cellulose is not the only readily and naturally available source of carb. Humans cannot digest cellulose (we have no celluase enzyme) and it passes though us as fibre - it has digestive uses but has no nutritional value. In fact digesting meats without fibre is a difficult process, so if early humans did have a high meat diet, we almost certainly still needed to keep eating plant matter to help it through. (My theory is cellulase used to be produced and used in the Appendix, which has since atrophied).
Carbs still represent a good emergency (and primary) source of energy and is one of the most basic and inevitable molecules in nature.
To fit in with their theory, there's plenty of starchy carbs available in the savannah - grass, seeds and root veg! It's almost certain humans scavenged for food when descending from the trees and protein from bone marrow than direct kills (unable to be eaten by other predators and scavengers even today) would be accessible to humans with a simple stone tool - something which is not beyond the intelligence of chimps.
What is also probable, by following the fossil evidence for human migration from Africa to Mesopotamia, is that we followed the African coastline. That means food from fish protein, not animal protein, and with the higher polyunsaturated and omega 3 fats in fish, it would also explain the uniquely human need for these fats as well, particularly for endurance muscle and brain proteins... (do not forget, a homosapien is an endurance animal, and the best of them). Although some animal meats such as Lamb, Deer or Bison contain good levels of Omega 3, it's still only about 10-15% of that you can get from fish.
And this is before I get onto the sugar conspiracy of today, where nearly every case of obesity can be attributed to an addiction to monosaccharide sugars, not fat.
So yes we do crave fat, but we crave carb as well and are just as able to get the calories we need from either energy sources. I don't think it's quite as clear cut as that article is making out, though it undoubtably has some basis in fact, as most ideas about naturalistic humans diets, exercise and lifestyle do.
Oh and btw, it's not just our brains that grew in place of our stomachs, but our brains also grew in places of our fast-twitch muscle fibres. We no longer needed the power to haul ourselves through the branches of trees, and were able to survive on smaller more efficient slow twitch endurance muscles instead. Probably an evolution that went hand-in-hand with a move to the savannah.
We only have one fat digesting enzyme and that comes from the pancreas, there is only amylase in the saliva which starts the break down of sugars. Protien only in the stomach from pepsin and fat is done in the small intestine via lipase as you said.While we have 3 types of fat digesting enzymes (1 in mouth, 1 in stomach, 1 in pancreas/dudodenum) and 2 types of carb digesting enzymes (1 in mouth, 1 in pancreas/dudedenum), we can actually breakdown and absorb carbs about twice as fast as we can fat. Fat has to go through an emulsification process, that is time consuming and complex, whereas carbs don't.
The part at which the article speaks of losing our need to crave carbs being evident from our less complex guts, is misleading. Complex guts are there to digest cellulose (plant matter) not carbs - or rather carbs from cellulose. But cellulose is not the only readily and naturally available source of carb. Humans cannot digest cellulose (we have no celluase enzyme) and it passes though us as fibre - it has digestive uses but has no nutritional value. In fact digesting meats without fibre is a difficult process, so if early humans did have a high meat diet, we almost certainly still needed to keep eating plant matter to help it through. (My theory is cellulase used to be produced and used in the Appendix, which has since atrophied).
Carbs still represent a good emergency (and primary) source of energy and is one of the most basic and inevitable molecules in nature.
To fit in with their theory, there's plenty of starchy carbs available in the savannah - grass, seeds and root veg! It's almost certain humans scavenged for food when descending from the trees and protein from bone marrow than direct kills (unable to be eaten by other predators and scavengers even today) would be accessible to humans with a simple stone tool - something which is not beyond the intelligence of chimps.
What is also probable, by following the fossil evidence for human migration from Africa to Mesopotamia, is that we followed the African coastline. That means food from fish protein, not animal protein, and with the higher polyunsaturated and omega 3 fats in fish, it would also explain the uniquely human need for these fats as well, particularly for endurance muscle and brain proteins... (do not forget, a homosapien is an endurance animal, and the best of them). Although some animal meats such as Lamb, Deer or Bison contain good levels of Omega 3, it's still only about 10-15% of that you can get from fish.
And this is before I get onto the sugar conspiracy of today, where nearly every case of obesity can be attributed to an addiction to monosaccharide sugars, not fat.
So yes we do crave fat, but we crave carb as well and are just as able to get the calories we need from either energy sources. I don't think it's quite as clear cut as that article is making out, though it undoubtably has some basis in fact, as most ideas about naturalistic humans diets, exercise and lifestyle do.
Oh and btw, it's not just our brains that grew in place of our stomachs, but our brains also grew in places of our fast-twitch muscle fibres. We no longer needed the power to haul ourselves through the branches of trees, and were able to survive on smaller more efficient slow twitch endurance muscles instead. Probably an evolution that went hand-in-hand with a move to the savannah.
The emulsification process of fat isn't complex it simply involves secretions from the liver via the gall bladder in the form of bile to emulsify the fats.
No animal can digest cellulose it is done via bacteria.
Also i'm not sure that the reason our brains have been able to grow bigger is because we lost muscle and gut mass, i don't think the human body has a maximum weight/volume limit.
Carbs are dirt cheap and can be refined easily its almost like making a drug more pure. Dangerous stuff . Like someone said wheat has been tampered with until it doesn't resemble it's ancestor. I don't think you can refine fat or protein? It's definately carbs which have f
ked us up, like a dream come true for the food industry, just plant and harvest, job done. Not like protein where you have to rear an animal for years.
ked us up, like a dream come true for the food industry, just plant and harvest, job done. Not like protein where you have to rear an animal for years. R300will said:
We only have one fat digesting enzyme and that comes from the pancreas, there is only amylase in the saliva which starts the break down of sugars. Protien only in the stomach from pepsin and fat is done in the small intestine via lipase as you said.
There's always one.Bedtime so I'll be brief.
Google lingual amylase, gastric amylase, pancreatic amylase, lingual lipase, pancreatic lipase, pepsin, trypsin. [academic schooling]
R300will said:
The emulsification process of fat isn't complex it simply involves secretions from the liver via the gall bladder in the form of bile to emulsify the fats.
Fats need to be deconstructed to glycerides then reassemble to triglycerides and emulsifying to then and build a chylomicron before absorbtion can occur by villi. Whereas carbs can be deconstructed by an amylase into a glucose form and absorbed by villi immediately. IIRC 30 mins to 2 hours for carbs. 3-4 hours for fats.R300will said:
No animal can digest cellulose it is done via bacteria.
It's done by cellulase, which is what the bacteria in the stomach of said animals have. Though my error is saying we could've made it, when we would've provided a place of it to be used. Possibly anyway. Not researched the idea.R300will said:
Also i'm not sure that the reason our brains have been able to grow bigger is because we lost muscle and gut mass, i don't think the human body has a maximum weight/volume limit.
I wasn't convinced by that statement either, though it did have a certain ring of sense to it. I see no reason why something would have to be sacrificed in order for another system to grow. More like it would atrophie or become a weakened gene through natural selection, over time, and the other system would appear to become dominant. ...but I was in keeping with topic.A major reason we can have a smaller gut and yet cope fine is that we cook food. Cooking is a massive evolutionary advantage - it takes far less time and energy to digest cooked foods, so you can gain a lot more energy from the food and gain it more quickly. Spending less energy on digestion means more energy for the brain.
Huntsman said:
rudecherub said:
For me, and I admit I'm no representative sample high fat high protien low carb works.
So help me out please, if I want to try this high fat and protein low carbs diet, what's in and what's out?| In | Out |
|---|---|
| Chicken | Sugar |
| Beef | Pasta |
| Eggs | Bread |
| Butter | Rice |
| Tinned sardines in tomato | Crunchy nut corn flakes |
| Mackeral | Potatoes |
As I noted up thread my tastes have shifted, so Crunchy Nut cornflakes would be icky sweet for me now in the way Frosties were.
The exception is a good bread, or rich cake does taste good, but I have them occasionally, as I would once have had lashings of cream say.
The caveat is when I eat carbs I feel hungry later on, even the next day I feel more hungry than usual.
Which reminds me of the times I have eaten usual buffet fare of sandwiches etc. Crimes I felt lousy, bloated and a bit icky afterwards. I took this to be a result of the shift in my metabolism.
I really just googled low carb vegetables. There were a few lists, stuck to the lowest ones for two weeks, added lower carb fruits after two weeks, IIRC after a couple of months I was over carbs, in as much as my taste buds found them in their refined states bland as hell.
Omelettes were a big help, as they can be thrown together, and have a lot of taste and ingredient options, cheese and cream really make a difference.
The hassle is that you can't rely on prepackaged stuff because so much sugar etc is hidden, but the plus side is you know what you are eating.
rudecherub said:
All I can say is personal experience.
I've stopped eating refined / high carbs, two years or so now.
After a couple of decades of believing the fat in fat out on y'belly logic I've found that - for me - bread and tatties do make me fat.
Right now my weight is stable, I can fit into trousers tailored for me at 16, and I eat cream, cheese, red meat all the time.
Basically I'm as thin as I've ever been, previously achieved by dieting and exercise, while doing very little exercise relatively speaking.
WTF is a tattie??I've stopped eating refined / high carbs, two years or so now.
After a couple of decades of believing the fat in fat out on y'belly logic I've found that - for me - bread and tatties do make me fat.
Right now my weight is stable, I can fit into trousers tailored for me at 16, and I eat cream, cheese, red meat all the time.
Basically I'm as thin as I've ever been, previously achieved by dieting and exercise, while doing very little exercise relatively speaking.
mattikake said:
There's always one.
Bedtime so I'll be brief.
Google lingual amylase, gastric amylase, pancreatic amylase, lingual lipase, pancreatic lipase, pepsin, trypsin. [academic schooling]
Fair enough, can't believe i've been schooled in biology by a personal trainer Bedtime so I'll be brief.
Google lingual amylase, gastric amylase, pancreatic amylase, lingual lipase, pancreatic lipase, pepsin, trypsin. [academic schooling]
mattikake said:
Fats need to be deconstructed to glycerides then reassemble to triglycerides and emulsifying to then and build a chylomicron before absorbtion can occur by villi. Whereas carbs can be deconstructed by an amylase into a glucose form and absorbed by villi immediately. IIRC 30 mins to 2 hours for carbs. 3-4 hours for fats.
That process isn't emulsification. The emilsification of fats is simply breaking down large lipid molecules into smaller ones to give a bigger surface area to increase the rate of digestion and absorption. Amylase breaks down starch into maltose which is then broken down and absorbed as glucose and at the epithelial surface of the gut.mattikake said:
I wasn't convinced by that statement either, though it did have a certain ring of sense to it. I see no reason why something would have to be sacrificed in order for another system to grow. More like it would atrophie or become a weakened gene through natural selection, over time, and the other system would appear to become dominant. ...but I was in keeping with topic.
Bowl of milk for the student vet, please.It's very simple to lose fat/weight
You need 1800 calls to run your systems per day, eat 1500 calls, you lose fat/weight as if by magic. That can be 1500 calls of lard or a loaf.... it does not matter.
Thats it.
Eating low carbs and more meat is lethal. A balanced diet and a little moving about will sort you out.
You need 1800 calls to run your systems per day, eat 1500 calls, you lose fat/weight as if by magic. That can be 1500 calls of lard or a loaf.... it does not matter.
Thats it.
Eating low carbs and more meat is lethal. A balanced diet and a little moving about will sort you out.
LordGrover said:
superkartracer said:
Eating low carbs and more meat is lethal.
I must know a lot of dead people then.http://articles.cnn.com/2001-03-20/health/protein....
Kidney failure. Consuming too much protein puts a strain on the kidneys, which can make a person susceptible to kidney disease.
High cholesterol . It is well known that high protein diets (consisting of red meat, whole dairy products, and other high fat foods) are linked to high cholesterol. Studies have linked high cholesterol levels to an increased risk of developing heart disease, stroke, and cancer.
Osteoporosis and kidney stones. High protein diets have also been shown to cause people to excrete more calcium than normal through their urine. Over a prolonged period of time, this can increase a person's risk of osteoporosis and kidney stones.
Cancer. One of the reasons high protein diets increase the risks of certain health problems is because of the avoidance of carbohydrate-containing foods and the vitamins, minerals, fiber, and antioxidants they contain. It is therefore important to obtain your protein from a diet rich in whole grains, fruits, and vegetables. Not only are your needs for protein being met, but you are also helping to reduce your risk of developing cancer.
Unhealthy metabolic state (ketosis). Low-carb diets can cause your body to go into a dangerous metabolic state called ketosis since your body burns fat instead of glucose for energy. During ketosis, the body forms substances known as ketones, which can cause organs to fail and result in gout, kidney stones, or kidney failure.
Ketones can also dull a person's appetite, cause nausea and bad breath. Ketosis can be prevented by eating at least 100 grams of carbohydrates a day.
Edited by superkartracer on Wednesday 27th June 14:51
The argument has moved on.
http://www.scientificamerican.com/article.cfm?id=c...
But saturated fats may ultimately be neutral compared with processed carbs and sugars such as those found in cereals, breads, pasta and cookies.
http://www.scientificamerican.com/article.cfm?id=c...
But saturated fats may ultimately be neutral compared with processed carbs and sugars such as those found in cereals, breads, pasta and cookies.
Fat and sugar in our food to some people can be very addictive. There's been studies on it and has been said that is can be as addictive as drugs. There's loads about it on google hear is just one link. http://www.huffingtonpost.co.uk/2011/11/03/fatty-a...
superkartracer said:
LordGrover said:
Fancy a lifting contest? Deads, squats, bench - you choose. 
, i can pick-up my great dane by the neck when he's st on the carpet That said those carbs came to him courtesy of trans fats hidden in home baking, and the vegetable oil from the deep fat fryer, which crucified his arteries.
Now he's eating high protein high fat and his blood results are some of the best his doc has seen.
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