Is body weight hereditary?
Explore the genetic variants associated with BMI and body weight.
Body weight and BMI are among the most studied traits in genetics. Twin studies show a substantial hereditary component, and genome-wide studies have found thousands of genetic loci linked to body weight.
What the analysis shows
DNAHelper shows which weight-associated variants your raw file contains and what research has linked them to. The result is a statistical association — not a weight prognosis. The analysis is based on the traits body mass index, body weight (10519 associated variants, strong evidence strength).
Which variants matter
FTO is the best-known weight gene — variants in its first intron are linked to both BMI and eating behaviour in studies worldwide. The MC4R region, which controls satiety, is also well established.
Beyond these there are thousands of weaker signals, many in genes affecting appetite, reward systems and energy turnover rather than fat tissue itself.
What research has actually found
The links to FTO and MC4R are replicated in millions of participants. Together, known variants explain a few percent of weight variation — the genetic signal is real but small per variant.
A polygenic score for BMI can shift probabilities in large groups, but says little with certainty about an individual person's weight.
What matters more than genes
Food environment, portion sizes, physical activity, sleep and stress together weigh far more than the individual variants. The same genetic profile can produce very different weight in different environments.
That is also why lifestyle habits are the factor that can actually be changed — genetics sets the preconditions, not the answer.
What the result means — and does not mean
The analysis is based on the traits body mass index, body weight (strong evidence strength). Associations are statistical — they describe populations, not destinies. Read how we grade evidence in our methodology.
Privacy: your file never leaves the browser
You pick your raw file locally — it is parsed and analysed entirely in your browser and is not uploaded for the standard analysis. The only exception is the optional DNA Chat feature where you, after explicit consent, can share selected variants. Read the privacy policy · What happens to your DNA file?
Compatible raw files
Works with raw data exports from MyHeritage, 23andMe, AncestryDNA and FamilyTreeDNA (.txt, .csv, .zip). The download guides show exactly where to find the file at your provider — and the file formats are explained here.
Also read: Method & science · All analyses · All traits · Muscle mass and genes