People with ‘obesity gene’ can still lose weight

October 4, 2016

“No matter how much I diet or exercise, I can’t seem to shift the weight!” Sound familiar? Let’s be honest, we all know someone who’s blamed their genes for not being able to lose weight. However, new research published in the BMJ shows that having the risk version of the FTO gene (the gene which has the biggest effect on body fatness) does not affect a person’s ability to lose weight. Dr Katherine Livingstone, Alfred Deakin Postdoctoral Research Fellow at the School of Exercise and Nutrition Sciences, sheds more light on the subject.

Climbing in Jeans in the “Gene Pool” Lawrence Berkeley Hall of Science by Colleen Proppe, CC BY-NC 2.0

How big is the problem of obesity?

Obesity rates are alarming high across the world. According to the Australian Bureau of Statistics, in Australia alone, 2 out 3 adults are overweight or obese. These numbers are in  line with estimates from around the world, where an estimated 2.1 billion adults are now overweight or obese.

Being obese is more of a problem than not being able to fit into your favourite jeans. Obesity has serious health implications and increases risk of diseases such as heart disease and type 2 diabetes.

What’s to blame for obesity?

Unsurprisingly, those evenings on the sofa devouring blocks of chocolate are not doing our waist lines much good! Unhealthy diets, where we eat lots of discretionary foods high in sugar and/or foods, such as chocolates and crisps, and where we don’t eat the recommended 2 serves of fruit and 5 serves of vegetables, will make it more likely that we gain weight. Similarly, not meeting physical activity recommendations of 2.5 hours of moderate intensity exercise (such as a brisk walk, swimming or pushing a stroller, or 1 and a quarter hours of vigorous intensity exercise such as jogging, fast cycling or heavy lifting) also has some blame for expanding our waist lines.

But if it’s all down to bad diet and not enough exercise, why aren’t we all overweight?

Is there such a thing as the “obesity gene”?

Research in hundreds of thousands of individuals around the world has shown that there are more than 90 genes associated with body fatness. The gene with the biggest effect is called FTO, often called the “obesity gene”. As much as 16% of people carry two copies of the risk version for FTO, meaning they are more likely to be heavier and 70% more likely to be obese.

So maybe some of us can blame FTO, and other genes inherited from our parents, for those extra kilos, but what does it mean for our ability to lose weight?

How does the FTO gene effect weight loss?

In this recent study Dr Katherine Livingstone, an Alfred Deakin Postdoctoral Research Fellow at Deakin University’s Institute for Physical Activity and Nutrition, was the lead author as part of an international collaboration of European and North American scientists that searched the literature on FTO and weight loss. The team identified over 9,500 people who had taken part in trials which used diet, physical activity or drugs to encourage weight loss.

After applying complex statistical analyses to the data, the team were surprised to discover that having the FTO gene had no effect on weight loss. Weight loss interventions were just as effective in people with the risk version of this gene as in everyone else. And the finding applied to everyone, whether men or women, younger or older people, and Caucasians or Black Americans.

Why are these findings important?

This is very important news for people trying to lose weight as it means that diet, physical activity or drug-based weight loss plans will work just as well in people who carry the FTO gene as those who don’t. To shift those kilos, instead of being tempted to blame our genes, we should improve our lifestyle behaviours by eating healthier diets and becoming more active.

Our genes may make us fatter, but they don’t prevent us from doing anything about it!

Dr Katherine Livingstone
Alfred Deakin Postdoctoral Research Fellow, School of Exercise and Nutrition Sciences, Deakin University