30/05/2018 05:08 BST | Updated 30/05/2018 05:08 BST

Is Being Overweight 'In Your Genes'? Nope, Says Study

Surprise: It's mainly your diet.

Peter Dazeley via Getty Images

Your body's ability to lose or gain weight is only marginally influenced by genetics, recent research reveals — it is mainly influenced by your diet.

Scientists at London's King's College examined how the gut processes and distributes fat.

To assess how much gut activity is genetic and how much is determined by environmental factors, the researchers examined stool samples from sets of twins, successfully identifying biomarkers in the faeces that corresponded to an increase in visceral fat around the waist.

The study found that 17.9 percent of gut processes which control fat storage are caused by hereditary factors, while 67.7 percent of gut activity is controlled by the "environment" in the gut — primarily the food and drink people consume — suggesting that the vast majority of people can control their weight through what they eat and how they live.

These findings come as health experts continue to issue warnings against rising obesity worldwide.

According to the Discovery Vitality ObeCity Index 2017, obesity in South Africa in particular is growing faster than the global average, with more South Africans obese in 2017 than in 2007.

King's College scientists hope the findings will pave the way for different and personalised obesity treatments in future.

Dr Jonas Zierer, one of the authors of the study, said: "This new knowledge means we can alter the gut environment and confront the challenge of obesity from a new angle that is related to modifiable factors such as diet and the microbes in the gut.

"This is exciting, because unlike our genes and our innate risk to develop fat around the belly, the gut microbes can be modified with probiotics, with drugs or with high-fibre diets."

"This exciting work in our twins shows the importance to our health and weight of the thousands of chemicals that gut microbes produce in response to food. Knowing that they are largely controlled by what we eat rather than our genes is great news, and opens up many ways to use food as medicine," said professor Tim Spector, the head of the King's College London's twin research group.