Carbohydrates: Can Your DNA Affect Your Carb Sensitivity?

Written by Wei Chen Yow
Posted on March 13, 2019

Have you ever wonder why some people can eat many bowls of rice without gaining a kilo, but you seem to gain some by just having a spoonful? Sometimes, we might want to blame our genes for it.

And maybe you’re right. Let’s see the behind scenes of how genes play a role in our ability to digest carbs.

What is this “Carb Sensitivity” you say?

When we mention the word “sensitive”, we usually point out as how responsive or vulnerable you are to the situation. So, when it comes to carb sensitivity, it refers to your body’s individual reaction to the carbohydrate group.

In other words…

The more carb sensitive you are, the longer or harder carbs take to process in your body. Though they sustain higher insulin levels but they have lower sensitivity in the body. This eventually means, you may have higher tendency of gaining the extra pound, likelihood of having insulin resistance and diabetes.

How do genes come into play?

Your genes act as the directory manual for your body. Your genes hold the important codes of your body.

They contain instructions that determine your features, such as the color of your hair, the shape of your eyes and whether you are short or tall. Our genes consist of two alleles, with one allele inherited by each parent. Alleles are responsible for a particular trait. Alleles are located at a locus called a genotype, and alleles are often expressed in letters like AA.

Depending on their associated traits, alleles are identified as either dominant or recessive.

Let’s look at an example for hair color.

Effects can be seen even if an individual only has one dominant allele (heterozygous). For example, the allele for blonde hair is dominant, thus you only need one copy of the ‘blond hair’ allele to have blond hair.

Effects can be seen if the individual has two copies of the recessive allele (homozygous). For example, the allele for red hair is recessive, thus you will need to have two copies of the ‘red hair’ allele to have red hair.

Just so you know, we have tens of thousands of genes making you become you today! And genotype varies from person to person like it varies from friend to another friend of the same age. Even a mother has some different features with her child.

What genes are linked to carbohydrate sensitivity?


Studies have found a connection between carbohydrate and Fatty Acid Binding Protein-2 (FABP2), a gene that codes for a protein in our small intestines. This protein binds with different types of fatty acids and allows them to be absorbed by the body.

In general, most of the population would have Ala/Ala allele pattern for FABP2, but some people would have the mutant-type — Thr/Thr or Ala/Thr. Research has found that about 30% of most population have the mutant-type (have Thr allele).

Now, when someone has either Thr/Thr or Ala/Thr for FABP2 gene, the protein that binds to fatty acids will become more efficient than normal. It’s so efficient that the speed of fatty acid absorption will be doubled, causing an increase in fats in the blood stream.

A study published by Coletta and Kreider (2015) found that FABP2 genotype in overweight people in comparison with normal weight people found that, people who are more on the heavy side tend to contain the mutant-type allele patterns of FABP2.

Experts have found that FABP2 have a few genotypes – position that is linked with a higher sensitivity to carbohydrates. The mutant-type allele Thr is seen to be associated with insulin resistance that can lead to diabetes.

Here’s a closer glimpse in the table below showing how genotype works and affects us.

AA2 copies of the Thr allele in FABP2 is associated with higher sensitivity to refined carbs
GGNo higher sensitivity to refined carbs
AGOne copy of Thr allele is associated with a moderately increased sensitivity to refined carbs


Now let’s turn our attention to a gene called ADRB2 (Beta-2-adrenergic receptor). ADRB2 plays a role in how fats are processed in our body.

Scientists discovered two common mutant-type allele patterns of ADRB2, which takes place at Arg16Gly and Gln27Glu found in the gene. These gene codes work on binding adrenaline.

There are two recent meta-analyses that found out how the mutant-type allele pattern at these gene codes showed a higher connection with obesity risk, especially among Asians. Besides that, experts suggested that people with G (Gln27Glu) variant of the gene are more likely to have higher carbohydrate sensitivity.

A table below demonstrating how Gln27Glu within ADRB2 can have an impact on how well you respond to carbohydrate.

CCNo higher sensitivity to refined carbs
CGOne copy of G allele is associated with a moderately increased sensitivity to refined carbs
GG2 copies of the G allele is associated with higher sensitivity to refined carbs

What you can do?

This makes a lot more sense if you think about it. But before you start blaming your genetic inheritance, there are some simple things you can do to make up for it. Well, just because you are more ‘carb sensitive’ doesn’t mean you’re beyond help.

1. Eat fewer carbs, but don’t eliminate them completely

Go for healthy carbs that are high-fiber, nutrient-rich foods such as whole-grain bread, brown rice, beans and legumes, and fruits and vegetables. Low-carb diets may work wonders for some people but it’s noteworthy that low-carb does not mean no carb at all. Eating the right amount of protein, healthy fats and carbs will provide adequate nutrient in your body.

2.  Enjoy your food slowly

It may sound simple but we may tend to eat our food faster to match up with this fast-paced world. Let’s take our time to chew our food more thoroughly, allowing ourselves to enjoy the interesting flavors in every bite! This helps you to reduce chances of craving more foods which we end up overeat more than our body need.

3. Exercise

Stay active for 30 minutes a day can bring wonders to your health, from fewer cravings and a slimmer waistline. A study involving diabetic patients reported that resistance training – muscle strengthening helps to improve blood sugar levels and insulin sensitivity. So instead of heading out with a donut, grab your running shoes on the go!

Live better and smarter

Yes, we know… health and wellness can be pretty confusing at times. But it does not have to stay that way.

Let us help you know the inside out about this with DNA Explorer. Get to know the best diet, exercise and lifestyle plan that is personalised just for you!

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