Starch Adaptation And Metabolic Typing

[jono]

Could it be that some people are more adapted to a higher intake of carbs than others? Maybe such people are also mal-adapted to a high fat/protein diet?

"We found that copy number of the salivary amylase gene (AMY1) is correlated positively with salivary amylase protein level and that individuals from populations with high-starch diets have, on average, more AMY1 copies than those with traditionally low-starch diets."
http://www.ncbi.nlm.nih.gov/sites/entrez/17828263?dopt=Abstract&holding=f1000,f1000m,isrctn

"For example, the Yakut of the Arctic, whose traditional diet centers around fish, had fewer copies than the related Japanese, whose diet includes starchy foods like rice, Dominy said. The same pattern existed for two Tanzanian tribes--the Datog, who raise livestock, and the Hadza, who primarily gather tubers and roots."
http://www.ucsc.edu/news_events/text.asp?pid=1553

Also, check out the village where unique tubers may be upregulating people's hyaluronic acid levels, imparting youthfulness into old age. I'm sure other factors are involved, but still an interesting case:

http://www.appliedhealth.com/ABC_News_HA.html

Also, lactase persistence in folks with dairying ancestry indicates they make better use of the sugar lactose than others. It doesn't mean milk drinking is ideal, but maybe for some people carbs are less harmful than in other people.

Learn how culture is speeding up evolution:
http://www.sciam.com/article.cfm?id=culture-speeds-up-human-evolution

I personally do very well keeping carbs around 100 gram per day... but I also accept the fact that some people may be able to tolerate, maybe even thrive, on more carbs than that.

Maybe even among people of animal-dominant dietary backgrounds, females, who may have done more of the gathering could tolerate a little more carbs than males who did more hunting.

Of course there are also lifestyle factors involved in tolerance of carbs:

If you're an Olympic swimmer, you can eat a stack of pancakes everyday without gaining an inch:

"Michael Phelps consumes around 8-10,000 calories a day to fuel his body for all of the training he does."

video: http://2008gamesbeijing.com/michael-phelps-daily-diet-video/

[Baerdric]

If you're an Olympic swimmer, you can eat a stack of pancakes everyday without gaining an inch: Yeah, when I was the age of an Olympic swimmer I could too. But as happens to a lot of athletes, when the sugar spikes finally wore down my metabolism, I packed it on like a beer drinking trucker.

I don't doubt that there are different levels of carb tolerance. I just don't think we know that one person is now and will always be at that level of tolerance - enough to say there are "types" of people.

My FIL often asks me (and bless his heart, I often repeat my answer to refresh his memory) "What about those skinny people in Japan I saw during the occupation who ate nothing but rice?"

Well, they ate a lot more than just rice, and before the preparation for a world war they had an even wider variety that didn't include so much rice, and all the people he saw were still fairly new to that diet and hadn't had the decades of damage it takes to ruin your metabolism

Find those same people today, and if they are still eating nothing but rice, you will see fat, sick, toothless people, genetic tolerance or not.

Which we do see now, by the way, in China and parts of SE Asia and India. You see it in Japan too, but that's not a fair comparison because they are largely Americanized now.

[jono]

>>>I just don't think we know that one person is now and will always be at that level of tolerance - enough to say there are "types" of people.<<<

Yeah. drawing lines and typing people is tricky because there doesn't seem to be a lot of research in this area, and there's so many factors involved.

But I could see a time, when enough genetic metabolic indicators are known, that people could receive useful dietary recommendations that match both their ancestry and lifestyle/health goals.

I just see, very often low carbers talk about carbs as detrimental to everybody's health, when consumed in significant amounts. But maybe some people are perfectly adapted to eat, say, 40% of calories from starchy foods.

I'm not talking about eating "nothing but rice"... yikes, reminds me of my snow-bum days eating nothing but top ramen, that got ugly.

[MeatGood]

Genetic typing is about the only way you could really tell.
We commonly just look at people and assume.
Someone might look at my friend and me. They may say, well, your friends appears to be able to eat anything and everything, and remains thin, while if I eat some pizza, I am going to gain some weight. Based on this casual observation why may assume that my friend has a high tolerance for carbs, or is genetically adapted to eating carbs.
But who knows what damage may be happening on the inside.
My friend might go on eating carbs, and I may stop and while he may remain thin, he might get cancer or something else, that cuts is health right down.

What I am saying is that the symptoms of things may not manifest in exactly the same way for everyone.
So really, without knowing a whole lot about genetics and how it all works, we really can’t screen and say, well this person is adapted 20% or 100% to this food type.

We can only guess based on empirical evidence that presents itself to us.

For those of us that gain weight for eating carbs, it’s a mixed blessing, because we can find out pretty easily that eating carbs is bad for us, the evidence is pretty obvious. The unlucky ones are the ones that the intolerance does not show up in weight gain, but by other less fortunate ways.