We’re often told that obesity is a genetic thing. That’s not true, at least not the way people often think of it.
In reality, our susceptibility to weight gain – compared to other people – is largely genetic. But whether we become obese or not depends on the environment and how we interact with it.
A new meta-analysis demonstrates this nicely. The FTO gene is strongly correlated with obesity, it’s likely one of the most powerful “obesity genes” in the world. Yet people with this gene are on average only one or a couple of kilos (a few pounds) heavier than average. Furthermore, people with this gene who take part in weight loss trials lose on average just as much weight as other people:
- The Guardian: Obesity Gene No Barrier to Weight Loss
- British Medical Journal: FTO Genotype and Weight Loss: Systematic Review and Meta-Analysis of 9563 Individual Participant Data from Eight Randomised Controlled Trials
This meta-analysis shows that people with an obesity-related gene can lose weight just like other people. The only difference is that they have a different baseline – in the same environment and with the same habits, they will always be slightly heavier. To reach and maintain the same weight as someone without those genes, they have to work a bit harder and smarter.
The world is certainly unfair. When it comes to maintaining a normal weight, some people face a bigger challenge than others. But our actions, habits and environments are far more important than our genes. Genes are not destiny.