DNA Traits · Nutrition & metabolism

Carbohydrate and protein intake

How much of the day's calories come from carbohydrate rather than protein and fat, as people reported it.

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Evidence · Replicated

What the research found

In the cited research, the A allele at rs838133 was associated with a slightly larger share of calories from carbohydrate and a smaller share from protein and fat.

GG: Lower carb
AG: Middle
AA: Higher carb

Slight effect

What the study found

In the study, each copy went with share of daily calories from carbohydrate about 0.26 percentage points of daily calories higher on average.

European-ancestry adults in the CHARGE replication cohorts (BMI-adjusted model) · 32,545 people · Table 2A, rs838133 carbohydrate row, replication columns (the heading prints 'Replication (n = 32,545)'); the footnote states 'Increasing beta indicate % of total energy higher intake of macronutrient'Genome-wide meta-analysis of macronutrient intake of 91,114 European ancestry participants from the cohorts for heart and aging research in genomic epidemiology consortium (Merino et al., 2019)

Evidence: Genome-wide meta-analysis with independent replication
Who was studied: European ancestry (US DietGen cohorts, with CHARGE and UK Biobank replication)

1000 Genomes Project

How common each genotype is

How common each genotype is in the 1000 Genomes Project, by region
Region	GGLower carb	AGMiddle	AAHigher carb
All regions2,504 people	62%	30%	8%
Africa661 people	54%	39%	7%
The Americas347 people	59%	32%	9%
East Asia504 people	99%	1%	Not seen
Europe503 people	34%	47%	19%
South Asia489 people	66%	30%	4%

Among the 2,504 people of the 1000 Genomes Project, in five world regions. These percentages describe groups of people, never anyone’s chance of having a trait.

Ancient genomes

Through time

How often the studied letter was read in ancient people, era by era, in the region chosen.

Region

Through time: Europe
Before farmingbefore 6500 BC	17%12 of 69 copies read
First farmers6500 to 3000 BC	33%336 of 1,008 copies read
Bronze Age3000 to 1200 BC	39%377 of 969 copies read
Iron Age and Antiquity1200 BC to AD 600	48%564 of 1,184 copies read
Middle AgesAD 600 to 1500	42%232 of 550 copies read
Today1000 Genomes	43%428 of 1,006 copies

Neanderthal and Denisovan genomes

Altai Neanderthal: No copies
Vindija Neanderthal: No copies
Chagyrskaya Neanderthal: No copies
Denisovan: No copies

For most ancient people only one of their two copies can be read, so these counts are copies read, not people. Close relatives, repeated samples and samples the archive marks as unreliable are left out. Damage in old DNA can fake this letter, so it is counted only from samples treated to remove that damage and from high-quality genomes. Ancient genomes from the Allen Ancient DNA Resource (AADR v66): 15,136 people.

rs838133

The marker

Gene or region: FGF21
Marker: rs838133
Location: Chromosome 19 · GRCh37 49,259,529 · GRCh38 48,756,272
Letters studied: A and G, with A as the studied allele

A DNA Traits report reads this marker in your raw DNA file and shows which of the three genotypes is yours, with how common it is. It counts the copies of the studied allele; it does not measure the trait itself.

Marker: FGF21 · rs838133
Location: Chromosome 19 · GRCh37 49,259,529 · GRCh38 48,756,272
Studied allele: A
Published statistic: Per A, percent of total energy: carbohydrate +0.264 (SE 0.054), P 5.2e-7 in replication (n 32,545); +0.252 (0.034), P 7.7e-14 discovery plus replication; +0.212 (0.033), P 1.1e-10 in UK Biobank; fat -0.152 and protein -0.093 in replication (Merino 2019 Table 2). Chu 2013 Table 1, protein (BMI-adjusted): DietGen -0.12 (0.03), P 2.3e-6; CHARGE -0.10 (0.03), one-sided P 7.3e-4; joint -0.11 (0.02), P 7.9e-9, n 68,968 (Table 2A, rs838133 carbohydrate row, replication columns (the heading prints 'Replication (n = 32,545)'); the footnote states 'Increasing beta indicate % of total energy higher intake of macronutrient')
1000 Genomes Project phase 3, people with 0, 1 and 2 copies: All regions 1555 / 755 / 194 · Africa 360 / 257 / 44 · The Americas 204 / 111 / 32 · East Asia 498 / 6 / 0 · Europe 171 / 236 / 96 · South Asia 322 / 145 / 22

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Limits

What it cannot tell you

Diet was self-reported in food questionnaires, and the shift per copy is a fraction of a percent of daily calories.

Novel locus including FGF21 is associated with dietary macronutrient intake (Chu et al., 2013)

The same topic

More in Nutrition & metabolism

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