What you carry at this position in your DNA and what research says about it.
Weight and Metabolic Risk: 6/10 evidence, 30 publications.
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Sample genotype (not yours): G/G
Typical Weight and Metabolic Risk
Carrying two copies of the G allele is associated with a typical body mass index and a lower baseline risk for metabolic complications. This genotype represents the standard genetic baseline for weight management and lipid levels.
What this genotype means: Typical body mass index; Favorable HDL cholesterol levels; Lower risk of metabolic syndrome.
Sample genotype (not yours): G/T
Slightly Increased Weight and Metabolic Risk
Carrying one copy of the T allele is associated with a slightly higher body mass index and a modest increase in metabolic risk. Regular physical activity can help counteract these genetic tendencies.
What this genotype means: Slightly higher average BMI; Mildly increased metabolic syndrome risk; Slightly lower HDL cholesterol.
Sample genotype (not yours): T/T
Increased Risk of Obesity and Metabolic Issues
Carrying two copies of the T allele is associated with a higher body mass index and an increased risk of metabolic syndrome. Engaging in consistent physical exercise is a powerful way to mitigate this genetic predisposition.
What this genotype means: Higher average body mass index; Increased risk of metabolic syndrome; Lower HDL cholesterol levels.
Gene function and biological role
Gene Function: The FTO gene encodes an enzyme known as alpha-ketoglutarate-dependent dioxygenase, which plays a critical role in regulating energy homeostasis, appetite, and fat metabolism. It is highly expressed in the brain's hypothalamus, a region that controls hunger and satiety. Research shows that FTO influences how the body senses nutrients and manages fat storage. Certain variations in this gene are strongly linked to differences in body mass index and the risk of obesity. Interestingly, the effects of FTO variants on weight can be significantly modified by lifestyle factors such as physical activity.
Variant Impact: Located within an intron of the FTO gene, rs3751812 is a single nucleotide polymorphism closely linked to metabolic health. Although it is located in a non-coding region, it is tightly co-inherited with other well-known obesity-related FTO variants. The T allele of rs3751812 is highly correlated with the risk-increasing alleles of other FTO markers, making it a reliable indicator of genetic susceptibility to weight gain. Studies have shown that this specific variant is associated with higher BMI, elevated metabolic syndrome risk, and altered lipid profiles. It has been particularly useful in fine-mapping obesity risk across diverse ancestral populations, including those of African and Asian descent.
Key Insight: Regular physical activity has been shown to actively blunt the genetic weight-gain influence of this variant, meaning lifestyle choices can directly override your genetic predisposition.
Location: FTO. Chromosome 16 · 16q12.2 · 53.8 Mb
Estimated prevalence by population
Global 51.2%; European 35.3%; African 81.1%; East Asian 72.0%; South Asian 47.3%; Americas 52.8%; Ashkenazi 24.9%; Finnish 36.2%; Middle Eastern 41.3%; Amish 29.0%.
Estimated GG genotype frequency.
Global 38.1%; European 48.2%; African 17.9%; East Asian 25.7%; South Asian 42.9%; Americas 39.7%; Ashkenazi 50.0%; Finnish 47.9%; Middle Eastern 45.9%; Amish 49.7%.
Estimated GT genotype frequency.
Global 10.8%; European 16.5%; African 1.0%; East Asian 2.3%; South Asian 9.7%; Americas 7.5%; Ashkenazi 25.1%; Finnish 15.9%; Middle Eastern 12.8%; Amish 21.3%.
Estimated TT genotype frequency.
Showing effects for G/G genotype
Cardiovascular & Metabolic
Obesity & Body Composition
Body Mass Index. Evidence: 8/10. Source: PMID 28448500. Typical BMI.
Metabolic Syndrome & Insulin Resistance
Metabolic Syndrome. Evidence: 6/10. Source: PMID 38201907. Typical Risk.
Lipids & Cholesterol
HDL Cholesterol. Evidence: 6/10. Source: PMID 30275531. Higher HDL.
Gout & Uric Acid
Uric Acid Levels. Evidence: 8/10. Source: PMID 38658550. Typical Levels.
Showing effects for G/T genotype
Body Mass Index. Evidence: 8/10. Source: PMID 28448500. Slightly Higher BMI.
Metabolic Syndrome. Evidence: 6/10. Source: PMID 38201907. Slightly Higher Risk.
HDL Cholesterol. Evidence: 6/10. Source: PMID 30275531. Slightly Lower HDL.
Uric Acid Levels. Evidence: 8/10. Source: PMID 38658550. Slightly Higher.
Showing effects for T/T genotype
Body Mass Index. Evidence: 8/10. Source: PMID 28448500. Higher BMI.
Metabolic Syndrome. Evidence: 6/10. Source: PMID 38201907. Increased Risk.
HDL Cholesterol. Evidence: 6/10. Source: PMID 30275531. Lower HDL.
Uric Acid Levels. Evidence: 8/10. Source: PMID 38658550. Higher Levels.
What this genotype means for the people who carry it
Sample genotype: GG (Homozygous)
Carrying two G alleles at this FTO locus represents the standard genetic baseline for weight management. This genetic profile is associated with a typical body mass index (BMI) and a lower risk of obesity compared to carriers of the T allele. Individuals with this genotype generally exhibit higher levels of beneficial HDL cholesterol, which supports cardiovascular health. Research also indicates a lower baseline risk for metabolic syndrome and type 2 diabetes. Furthermore, uric acid levels tend to remain within a typical range, reducing the genetic predisposition to gout. While genetics provide a favorable baseline, maintaining a balanced diet and regular exercise remains essential for overall metabolic wellness. This genotype is considered the standard genetic baseline across most global populations.
Typical body mass index; Favorable HDL cholesterol levels; Lower risk of metabolic syndrome.
Sample genotype: GT (Heterozygous)
Carrying one copy of the T allele creates an intermediate genetic profile for weight and metabolic traits. This intermediate profile is linked to a slightly higher average body mass index (BMI) and a modest increase in the risk of obesity. Research shows that carriers of the T allele may experience slightly lower levels of protective HDL cholesterol. There is also a mildly elevated risk for metabolic syndrome and type 2 diabetes compared to the GG genotype. Additionally, studies suggest a slight increase in serum uric acid levels, which is a risk factor for gout. Fortunately, clinical studies demonstrate that regular physical activity is highly effective at reducing or even neutralizing the genetic weight-gain influence of this FTO variant. Adopting a lifestyle that includes consistent aerobic exercise can help bridge the gap and maintain a healthy metabolic profile.
Slightly higher average BMI; Mildly increased metabolic syndrome risk; Slightly lower HDL cholesterol.
Sample genotype: TT (Homozygous)
Carrying two copies of the T allele represents the highest genetic predisposition to weight gain at this locus. This genetic profile is associated with a higher body mass index (BMI) and an increased susceptibility to obesity. This genetic profile is associated with the highest susceptibility to weight gain and metabolic complications at this locus. Individuals with this genotype often exhibit lower levels of beneficial HDL cholesterol and higher levels of LDL cholesterol. There is a significantly increased risk of developing metabolic syndrome and type 2 diabetes. Furthermore, this genotype is associated with elevated serum uric acid levels, which can increase the risk of gout. Crucially, research highlights that physical activity is an incredibly powerful tool for TT carriers, as regular exercise has been shown to dramatically blunt the genetic effect on BMI. Engaging in active exercise for at least thirty minutes several times a week can help manage these genetic risks effectively.
Higher average body mass index; Increased risk of metabolic syndrome; Lower HDL cholesterol levels.
Variants with shared genetic architecture
rs11075995 · FTO Gene · Chr 16 · Breast Cancer Risk
rs11642015 · FTO Gene · Chr 16 · Weight and Diabetes Risk
rs1421085 · FTO Gene · Chr 16 · Obesity and Weight Gain
Content updated August 2026.
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