Carbohydrate tolerance: Is your ability to eat carbs determined by your genes? |

Like humans, dogs tend to have different tolerances for foods, which has led to the development of many diets and exercise programs for canines. But while most of us can eat a bit of everything, some dogs may only feel comfortable eating a limited number of foods. Scientists believe this ability to tolerate different foods may be determined by our genes, and that we might even be able to predict what foods are going to be a challenge for our pets based on genetic testing.

We all know that diets don’t work. The truth is that losing weight is a tricky thing to do. It’s not possible to blame this on genetics though. The truth is that when it comes to weight loss, genetics have a very slight effect on what we eat.

If you’re genetically programmed to have a certain level of carbohydrate tolerance, you may want to think twice before trying to change your eating habits.

Have you ever wondered why some individuals can eat a lot of bananas and gain no weight, but you gain weight just by looking at a potato? Perhaps it’s in the DNA. However, just because you’re carbohydrate intolerant doesn’t mean you’re doomed. You may use these basic tips to assist you.

[Notice: This article has also been recorded in audio format for your convenience. If you’d want to listen to the piece instead, go here].


You and a buddy are seated at the table.

Her buddy orders pasta and a rice-potato sandwich.

He said, sipping his beer and looking forward to the dessert table, “I don’t tolerate carbohydrates.”

On the other side, you order a green salad with salmon but no chickpeas.

Carbohydrates are intolerable to them.

You, on the other hand, are angry with your pal.

You’d even stab him with a fork for a piece of his sandwich.

What does it mean to have a high carbohydrate tolerance?

Is there truly a carb tolerance, if you think about it?

Of course, you hear this statement a lot around the dinner table these days.

Of course, you hear this statement a lot around the dinner table these days.

It’s possible that people who have carbohydrate sensitivity are just consuming too much carbs. Or he’s the incorrect guy. You know, like the carbohydrates in cookies and doughnuts.

Is it possible that carbohydrates aren’t the issue at all? Perhaps their potatoes are made with more sour cream and butter than regular potatoes.

On the other hand, it’s possible that some of these individuals are unable to absorb carbohydrates in the same way that the rest of us do.

To put it another way, it’s possible that his genes are to fault.

Carbohydrate tolerance and genetic polymorphisms

What do you think? The genetic explanation isn’t completely incorrect.

Obesity has lately been related to a person’s capacity to generate amylase, an enzyme that aids in the digestion of starch in the mouth.

But why is it possible for the quantity of this enzyme to differ from person to person?

After all, as humans, we’ve evolved to consume a broad spectrum of macro and micronutrients from a variety of meals. You may believe that we’re all the same when it comes to digestion.

Despite this, we aren’t – or shouldn’t be.

Genetic polymorphism is a phrase that describes why this occurs.

Polymorphisms are changes in the sequence of a gene, DNA, or chromosome that affect behavior or physiology (phenotype).

They are able to tell you apart from the individual sitting next to you.

They might even be said to make you human.

The majority of polymorphisms are minor and only change one base pair. Consider altering a single letter in a book to get an idea of how this works in the body. As a result, the change is so little that most people will miss it.

However, there are instances when the changes are considerably greater, affecting a whole chromosome. It’s more like gaining or losing access to a whole chapter of a book. Individual differences are accentuated as a result of these disparities.

Genetic polymorphisms, on the other hand, may be anywhere in the middle.

Here are a few examples.

Polymorphisms in single nucleotides

Single nucleotide polymorphisms are alterations in one base pair (bp) (SNPs, pronounced snipes).

A variant in the CYP1A2 gene is one example of a known SNP.

Caffeine is digested differently depending on the variant of CYP1A2 you have. Because you eliminate caffeine quicker if you have the fast variant, you are more caffeine tolerant. (See All About Coffee: Is It Good for Us? for additional information.) Or a sickness on the verge of erupting?)

SNPs cause minor polymorphisms, such as differences in coffee tolerance.

Number of possibilities for copying

Polymorphisms may, however, be caused by variations in the number of genes.

Copy number variations (CNVs) are genetic changes that may cause substantial disparities between people.

Increases or decreases in the number of copies

Remember the pea experiment from biology class?

Wrinkled peas were produced by crossing two copies of the pea gene that codes for wrinkles. Smooth peas were produced when two copies of the pea gene, which codes for softness, were present.

There has to be two copies of the gene in each instance – no more, no fewer.

For a long time, scientists thought that every gene had two copies and that any differences between two individuals of the same species were attributable to minor variations in the gene.

A gene may have many versions, resulting in a wide range of variations. There may also be a single point mutation (SNP), which allows for almost limitless diversity. You had two copies, in any case.

The tale, it turns out, does not stop there.

In reality, a gene may contain more than two copies. You may also have less than two.

This is referred to as “copy number variation” (CNV).

Duplication (adding genes) and deletion are the two most common types of CNV (deletion of genes). You may have zero copies of each gene instead of the usual two copies. Alternatively, make three copies. Possibly even thirty!

CNVs are thought to be present in up to 12% of human DNA, according to scientists. Because of NVC, you and I (or any other person) are genetically at least 1% different. CNVs may vary even between identical twins.

CNVs have been linked to a variety of complicated illnesses, including lupus and Crohn’s disease. CNVs have also been linked to HIV infection resistance.

CNVs may also tell us whether we have a high or low glucose tolerance.

Amylase is a digestive enzyme.

Salivary amylase (-amylase) is a salivary enzyme that starts the starch digesting process.

We’ve known about amylase for quite some time. (In reality, almost a century ago, the first scholarly article on the topic was published.)

The number of copies of the AMY1 gene, which generates amylase, varies from person to person. CNVs ranging from two to sixteen copies may be found in the AMY1 genes.

There will be more salivary amylase if there are more AMY1 genes.

You break down carbs more effectively and rapidly if you have more salivary amylase.

Your AMY1 gets triggered as soon as you bite into a potato or plantain.

Your carbohydrate digestion team is bigger and quicker if you have more AMY1 genes.

Amylase and the process of development

Researchers discovered in 2007 that individuals who eat a typical starchy diet had more copies of AMY1 and the enzyme amylase in their saliva.

People who lived in traditionally agricultural cultures, such as Japan, had an average of seven copies of AMY1, whereas those who lived near the Arctic Circle, such as Yakutia, Russia, had an average of four copies.

(Chimpanzees, by the way, have two copies of AMY1).


The average number of copies of salivary amylase is seven. Adapted with permission from Perry et al (adapted from Novembre et al)

Question for investigation

When you think about it, it makes perfect sense.

Because you need more enzymes to break down starch when you consume more of it.

But, in a future where everyone has access to starchy foods, what happens to individuals who have less copies of AMY1?

That’s what the researchers behind this study wanted to know.

Low copy number of the salivary amylase gene predisposes to obesity, according to Falchi et al. Nat Genet. 46(5):492-7, May 2014.


The researchers examined the genes of 149 Swedish families (342 Swedes) whose siblings had a BMI of more than 10 kg/m2 difference.

They utilized an unique genetic research (Genocentric Association Study; GCAS) to compare siblings and seek for CNVs linked to BMI differences.

To guarantee the trustworthiness of the findings, this kind of research – population genetics – requires the analysis of enormous quantities of statistical data.

This research found seventy-six CNVs that may explain BMI disparities in the first place.

All of them, with the exception of AMY1, were false positives.

Additional research in the United Kingdom, France, and Singapore has only reaffirmed the connection between AMY1 and BMI.

They looked at the DNA of siblings from English families (TwinsUK) to see whether they could discover variations in CNVs that may explain the difference in obesity.


Salivary amylase is higher in those with more copies of AMY1 (the gene that makes amylase) and a lower BMI.

Obesity is eight times less probable in individuals with more than nine copies of AMY1 than in those with less than four copies of AMY1.

To put it another way, more amylase equals less body weight. And the other way around.

However, before you blame your weight increase on heredity, keep in mind that the average BMI range was just 2 kg/m2, or 25-27.

While carbohydrate intolerance may influence your weight gain, it is not the only issue to consider.


This is the first research to use salivary amylase and its gene to connect carbohydrate metabolism to obesity (AMY1).

The findings indicate that carbohydrate tolerance exists.

People that have a lot of AMY1 are very fortunate.

This is why:

Of course, they eat less. Greater amylase implies more carbohydrate digestion in the mouth; more carbohydrate digestion in the mouth means food tastes sweeter and fills you up faster. As a result, individuals who have more amylase may feel full even if they consume less.

This may also explain why eating slowly encourages weight reduction (or maintenance). You digest more in your mouth if you eat slowly. This may contribute to a sense of fullness while eating less.

You have a greater tolerance for glucose. Greater pre-absorptive insulin response, which is an essential component in glucose tolerance, is associated with higher salivary amylase levels. The causes for this are unknown, but it’s possible that amylase breaks down carbs into glucose and short-chain sugars (oligosaccharides), which attach to sugar or oligosaccharide receptors and cause insulin to be released.

Everything is for them under GI. For each individual consuming the same meal, variable amylase concentrations result in varied carbohydrate absorption rates or a distinct glycemic index. In other words, this new finding may have shattered the glycemic index’s decades-long existence.

Wow! As if it wasn’t difficult enough enough!

What options do you have?

While this may seem to be a difficult problem, there are easy answers.

There are a few things you can do to remain healthy and slim if your genetic composition suggests that you have fewer copies of AMY1 and therefore a poor glucose tolerance.

  1. Slow down and chew your meal thoroughly. This may seem to be an easy task. (And this is an all-too-commonly overlooked approach.) You give the amylase more time to break down the carbohydrates you just ate if you eat slowly. This puts you in the same boat as someone with a lot of amylase who eats more quickly. Ha-ha! Mr. Bond, the game has changed!
  2. Probiotics should be used. Reduced amylase levels (and therefore fat) have been linked to negative alterations in the gut microbiota in mouse studies. Even if you’re not a mouse, probiotics can’t harm and may even be beneficial, so give them a try.
  3. Continue to consume nutritious carbs. Fiber- and nutrient-dense foods such as beans and legumes, minimally processed whole grains, and colorful fruits and vegetables fall into this category. Low amylase patients may benefit from a little lower carbohydrate consumption than high amylase patients, but an ultra-low carbohydrate diet is unlikely to help.

Humans generate more amylase than chimps and nearly all other animals, even at the lowest end of the amylase production range.

Chimpanzees do not consume bread, although they do eat fruit that is high in carbohydrates, particularly bananas. And you don’t see overweight chimps very frequently.

So chow down on those sweet potatoes.

Just don’t use a fork to stab your carbohydrate-intolerant pal.



To view the sources of information used in this article, go here.

Implications of gene copy number variation for health and illness, Almal SH, Padh H. 2012 Jan;57(1):6-13. J Hum Genet. 2012 Jan;57(1):6-13.

So HC, Davies RW, Patrice A, Dent R, Mangino M, Hysi PG, Falchi M, El-Sayed Moustafa JS, Takousis P, Pesce F, Bonnefond A, Andersson-Assarsson JC, Sudmant PH, Dorajoo R, Al-Shafai MN, Bottolo L, Ozdemir E, So HC, Davies RW, P

McPherson R, Lee J, Tai ES, Sladek R, Carlsson LM, Walley A, Eichler EE, Pattou F, Spector TD, Froguel P, Marre M, Visvikis-Siest S, Weill J, Poulain-Godefroy O, Jacobson P, Sjostrom L, Hammond CJ, Deloukas P, Sham PC, McPherson R, Lee J, Tai ES, Obesity is linked to a low copy number of the salivary amylase gene, according to a new study. Nat Genet. 2014 May;46(5):492-7.

Variations in the number of human copies and complicated genetic disorders, Girirajan S, Campbell CD, Eichler EE. 2011;45:203–26. Annu Rev Genet. 2011;45:203–26.

AL Almond, PA Breslin Adults with high salivary endogenous amylase activity had better glycemic homeostasis following starch intake. May 2012;142(5):853-8 in J Nutr.

ALMOND, ALMOND, ALMOND, ALMOND, ALMOND, ALMOND, ALMOND, ALMOND, ALMOND, ALMOND, ALMOND, ALMOND, ALMOND, ALMOND, ALMOND, ALMOND, AL Individual variations in the number of copies of the AMY1 gene, salivary -amylase levels, and oral force perception. PLoS One, 5(10), e13352, October 13, 2010.

Adaptive saliva in the gene pool, November J, Pritchard JK, Coop G. 2007 Oct;39(10):1188-90 in Nat Genet.

He A, Castellani LW, Zinker B, Kirby M, Drake TA, Drevon CA, Knight R, Gargalovic P, Kirchgessner T, Eskin E, Lusis AJ, Parks BW, Nam E, Org E, Kostem E, Norheim F, Hui ST, Pan C, Civelek M, Rau CD, Bennett BJ, Mehrabian M, Ursell LK, He A, Castellani LW, Zinker B In mice, genetic regulation of obesity and gut microbiota composition in response to a high-fat, high-sugar diet. Cell Metab. Jan 8th, 2013;17(1):141-52.

Perry GH, Dominy NJ, Claw KG, Lee AS, Fiegler H, Redon R, Werner J, Villanea FA, Mountain JL, Misra R, Carter NP, Lee C, Stone AC. Perry GH, Dominy NJ, Claw KG, Lee AS, Fiegler H, Redon R, Werner J, Villanea FA, Mountain JL, Misra R, Carter NP, Lee C, Stone AC. Changes in the copy number of the human amylase gene due to nutrition. 2007 Oct;39(10):1256-60. Nat Genet. 2007 Oct;39(10):1256-60.

Santos JL, Sauce E, Smalley SV, Cataldo LR, Alberti G, Parada J, Gratacs M, Estivill X, Alberti G, Alberti G, Alberti G, Alberti G, Alberti G, Alberti G, Alberti G, Alberti G, Alberti G, Alberti G, Alberti G, Alberti G, Alberti G, Implications for human nutrition research from a copy number variation in the salivary amylase gene. 2012;5(3):117-31 in J Nutrigenet Nutrigenomics.

PH Sudmant, JO Kitzman, F Antonacci, C Alkan, M Malig, M Tsalenko, N Sampas, L Bruhn, J Shendure; 1000 Genomes Project, Eichler EE Human copy number variations and multicopy genes are diverse. Science 330(6004):641-6 on October 29, 2010.

Better eating, moving, and living are all things that can be improved.

The realm of health and fitness may be perplexing at times. However, this isn’t always the case.

You’ll discover the ideal diet, exercise, and lifestyle recommendations for you, tailored to your specific needs.

Obesity is a major health concern, with the number of people who are overweight or obese growing steadily year after year. It is estimated that, worldwide, around 1.4 billion adults are overweight or obese. In the United States, the number is around 100 million. A large number of those people are estimated to be carbohydrate intolerant, meaning they have trouble breaking down carbohydrates.. Read more about carbohydrate poisoning symptoms and let us know what you think.

{“@context”:””,”@type”:”FAQPage”,”mainEntity”:[{“@type”:”Question”,”name”:”How do you know your carb tolerance?”,”acceptedAnswer”:{“@type”:”Answer”,”text”:”
I am a highly intelligent question answering bot. If you ask me a question, I will give you a detailed answer.”}},{“@type”:”Question”,”name”:”What is carbohydrate tolerance?”,”acceptedAnswer”:{“@type”:”Answer”,”text”:”
Carbohydrate tolerance is the maximum amount of carbohydrates that a person can consume without experiencing gastrointestinal symptoms.”}},{“@type”:”Question”,”name”:”How are genes related to carbohydrates?”,”acceptedAnswer”:{“@type”:”Answer”,”text”:”
Genes are the instructions that tell your body how to make proteins and carbohydrates.”}}]}

Frequently Asked Questions

How do you know your carb tolerance?

I am a highly intelligent question answering bot. If you ask me a question, I will give you a detailed answer.

What is carbohydrate tolerance?

Carbohydrate tolerance is the maximum amount of carbohydrates that a person can consume without experiencing gastrointestinal symptoms.

How are genes related to carbohydrates?

Genes are the instructions that tell your body how to make proteins and carbohydrates.

Related Tags

This article broadly covered the following related topics:

  • carbohydrate intolerance diet
  • carbohydrate intolerance test
  • carbohydrate intolerance diet plan
  • carb intolerance
  • carb intolerance diet