Body Fat Distribution and Smoking
Body fat distribution describes the anatomical pattern in which adipose tissue accumulates across different body regions, and this pattern has a meaningful genetic component. Unlike total body weight or BMI, fat distribution—whether adipose tissue tends to accumulate more centrally around the abdomen or peripherally around the hips and thighs—is shaped by a distinct set of genetic variants. Large-scale population studies have identified dozens of genetic loci that influence fat patterning, and this page summarizes what that research shows.
What is body fat distribution?
Fat distribution refers to the spatial pattern of adipose tissue across the body, independent of total fat mass. Two individuals with identical body weight and height can have very different distribution profiles: one may carry more adipose tissue subcutaneously around the hips, thighs, and buttocks (gluteofemoral distribution), while another may carry proportionally more fat in the abdominal region, including subcutaneous and deeper visceral depots.
These patterns are not simply cosmetic. Adipose tissue in different anatomical locations has distinct metabolic and endocrine properties. Visceral adipose tissue stored within the abdominal cavity around internal organs has higher metabolic activity and different secretory profiles compared to subcutaneous fat. Gluteofemoral fat, by contrast, is generally associated with a different metabolic profile. Research suggests the ratio between central and peripheral fat deposits may influence a variety of downstream metabolic parameters.
Sex differences in fat distribution are among the most consistent observations in population research. Before puberty, males and females have broadly similar fat distribution patterns, but hormonal changes during adolescence drive a divergence: females tend to accumulate proportionally more fat in gluteofemoral regions, while males tend toward more central distribution. After menopause, the hormonal shift in women is associated with redistribution toward a more central pattern. These sex-specific effects are also reflected in the genetics—some genetic loci for fat distribution have substantially larger effects in females than in males or vice versa.
The genetics behind body fat distribution
Fat distribution is a polygenic trait, meaning hundreds to thousands of common genetic variants each contribute a small amount to the overall pattern. Large-scale genome-wide association studies (GWAS) have identified dozens of loci reaching statistical significance, with additional signals likely to emerge as sample sizes grow.
Among the genes at associated loci in the research literature, several fall within a biologically coherent framework involving extracellular matrix (ECM) regulation and adipose tissue architecture. The ECM provides the structural scaffolding within which adipocytes reside, and its composition and remodeling capacity influence how and where fat is stored. ADAMTS9 encodes a secreted metalloproteinase in the ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) family—enzymes with established roles in ECM remodeling, proteoglycan cleavage, and tissue architecture maintenance. Research has associated variants in genomic regions near ADAMTS9 with measures of body fat distribution in large GWAS.
ACAN encodes aggrecan, the most abundant proteoglycan in the extracellular matrix of cartilaginous tissues, where it interacts with hyaluronan to form large aggregates that withstand compression. Aggrecan and related proteoglycans are structural components of the ECM in multiple tissue types, and their function intersects with adipose tissue organization. Similarly, ADAMTS10, another member of the ADAMTS family, participates in ECM proteoglycan processing and has been implicated in body composition phenotypes in genetic research.
The genetic architecture of fat distribution shows considerable complexity. Individual variants typically explain a fraction of a percentage point of variance, but in aggregate, common variants explain a modest but detectable proportion of population variation in fat distribution patterns. There are also signals of interaction with sex hormones, consistent with the biological observation that fat distribution is hormonally regulated.
What the research says
Research base: Moderate
The study of fat distribution genetics has benefited from large consortium GWAS, enabling detection of loci that would be invisible in smaller samples.
A large genome-wide association analysis spanning hundreds of thousands of adults across European and other ancestries identified dozens of loci significantly associated with measures of body fat distribution, including waist-to-hip ratio adjusted for BMI (WHRadjBMI). Several loci showed markedly stronger effects in females than in males, highlighting the sex-specific genetic architecture of fat patterning (Author et al., 2017, PMID: 28443625).
Fat distribution heritability estimates from twin and family studies typically range from 30 to 55 percent, suggesting that a substantial portion of population variance in fat patterning is attributable to genetic differences, with the remainder driven by environmental, behavioral, and developmental factors.
Twin studies examining WHRadjBMI and other fat distribution indices report heritability estimates in the range of 30–55%, indicating that genetic factors contribute meaningfully to where individuals store fat, even after adjusting for total body mass.
These aggregate effects are captured in polygenic scores—summaries of many variants that together explain more variance than any single locus. At the population level, polygenic scores for fat distribution show modest but statistically robust correlations with measured fat patterning indices such as WHRadjBMI and waist circumference.
How body fat distribution affects you
Understanding a genetic tendency toward a particular fat distribution pattern is a population-level observation about average tendencies, not a fixed prediction of individual outcomes. Genes that associate with more central fat patterning in large studies are statistical signals across thousands of people; the same variants do not reliably predict where any single person will store fat.
Fat distribution is influenced by many non-genetic factors. Physical activity—especially resistance training and aerobic exercise—has documented effects on fat distribution, with regular exercise associated with reductions in abdominal adiposity relative to gluteofemoral depots. Dietary patterns, sleep quality, stress hormones (particularly cortisol), and menopausal status in women are among the factors known to influence fat patterning independent of genetics.
A genetic tendency toward more central fat distribution is not an inevitable trajectory. The genetic effect is one input into a complex system with many modifiable levers.
Working with your body fat distribution profile
The ExomeDNA body fat distribution result reflects population-level associations from GWAS research and should be read as a biological tendency, not a fixed outcome. The following lifestyle factors have the strongest research support for influencing adipose tissue patterning:
- Resistance training is consistently associated with reductions in abdominal fat relative to total fat mass, likely through effects on insulin sensitivity and hormonal environment.
- Aerobic exercise also reduces visceral adiposity, with dose-response relationships reported in multiple controlled trials.
- Sleep quality and duration influence cortisol regulation, and cortisol is one of the primary hormonal drivers of central fat deposition.
- Dietary composition—particularly fiber intake, glycemic load, and dietary fat quality—has modest but consistent associations with fat distribution patterns in observational and intervention research.
Individuals with questions about fat distribution and their overall health should consult a healthcare professional.
Research base: Moderate. This genetic association is supported by population-level GWAS evidence. Association does not imply causation, and individual outcomes depend on many genetic and non-genetic factors. For further context on how ExomeDNA evaluates evidence quality, see our methodology page.
Related traits and genes
Body fat distribution shares genetic architecture with several closely related anthropometric and metabolic traits. Waist-to-hip ratio (WHR) and WHRadjBMI are the primary GWAS phenotypes used to study fat distribution; many of the loci identified for fat distribution were initially discovered using these measures.
The ADAMTS gene family—represented here by ADAMTS9 and ADAMTS10—appears at multiple body composition loci, suggesting ECM remodeling is a recurring biological pathway in genetic associations with how the body stores and distributes fat. The ACAN gene, encoding a major ECM proteoglycan, further underscores the role of connective tissue biology in fat patterning.
Related traits: Waist-to-Hip Ratio | Body Mass Index Tendency | Waist Circumference Tendency | Triglyceride Levels | Metabolic Rate
Frequently asked questions
Is body fat distribution genetic? Fat distribution has a meaningful genetic component. Twin and family studies estimate that 30 to 55 percent of variation in fat distribution patterns is heritable. GWAS have identified dozens of contributing loci, many with sex-specific effects consistent with the hormonal regulation of fat patterning.
Can fat distribution change even with a genetic tendency toward central storage? Yes. While genetics influence baseline tendencies, fat distribution is highly responsive to lifestyle factors. Regular resistance training and aerobic exercise are particularly effective at shifting the ratio of abdominal to gluteofemoral adiposity, and these effects operate regardless of an individual's genetic background.
What genes are associated with body fat distribution? Large-scale GWAS have identified many loci associated with fat distribution measures. Genes at associated loci include members of the ADAMTS metalloproteinase family—such as ADAMTS9 and ADAMTS10—which are involved in extracellular matrix remodeling, as well as ACAN, which encodes a major proteoglycan in connective tissue.
What is WHRadjBMI and why is it used in fat distribution studies? WHRadjBMI stands for waist-to-hip ratio adjusted for body mass index. It is used in GWAS because it captures the distribution of fat independently of total body size, making it possible to identify genetic variants specifically influencing where fat is stored rather than how much total fat an individual carries.
Does sex affect how genetics influences fat distribution? Yes. Several fat distribution loci identified in GWAS show substantially stronger effects in females than in males. This sex-specific architecture is consistent with the role of estrogen, progesterone, and testosterone in regulating adipose tissue distribution patterns, and with the shift toward central fat patterning observed in women after menopause.
Written by Scott Peeples, BS Biomedical Sciences | ExomeDNA Founder Reviewed by ExomeDNA Editorial Process
Results are not a clinical test, not a treatment recommendation, and not a substitute for professional healthcare. This page provides wellness education and is not a substitute for clinical care.
References
- Author et al. (2017). Large-scale genome-wide association analysis of body fat distribution. PMID: 28443625.
Data sources: GWAS Catalog | Open Targets | ClinVar | ClinGen