One in 6 of us may carry an ‘obesity gene’ that experts say makes us more likely to be overweight or obese. Before you blame your genes (or accuse your mum) and resign yourself to growing ever larger, there are 2 things you should know.
1. The ‘fat gene’ can be controlled with exercise
2. Scientists don’t know exactly how the gene relates to obesity, but believe it’s concerned with appetite – so if you don’t over-eat, you’re unlikely to become overweight
Wave a white flag to weight loss?
You may feel like giving up if you have a hunch about your DNA, but don’t make the FTO gene, also known as the ‘fat gene’, a self-fulfilling prophecy.
It’s a genetic variant of FTO, which is the gene associated with fat mass and obesity, that’s linked to obesity, and research has shown that people carrying 2 copies of the gene are on average 3kg heavier than people who aren’t.
However, having the gene only makes you more likely to be overweight if you eat a diet high in energy density and don’t exercise.
The truth is, our exercise and eating habits have a greater impact than DNA when it comes to body shape. If you keep the calories down and make exercise part of your routine, you can overcome your genetic make-up.
A study by the Lund University Diabetes Centre suggested exactly that: even if you were unlucky in the genetics game, the critical factor is still what you eat.
Using data from 230,000 people, the research suggested that those with the gene had a greater chance of being overweight, but only if their usual food habits were high in fat. Those people whose diets were low in fat were no more likely to be overweight, despite the inherited risk, the study found.
“This shows that we are not slaves to our genes,” author of the study Emily Sonestedt says. “Even if we are born with an inherited predisposition to obesity, lifestyle is more important.”
The FTO gene affects the part of the brain that regulates appetite and tells you when you’re full. So, it could be that people with the gene don’t feel as full from eating fat as those without it. It's possible, therefore, that we consume more and gain weight, says Sonestedt.
Diets for your DNA?
It may be outrageously expensive, but it is possible to create a personalised diet based on a person’s DNA.
Researchers in America gave 138 women a cheek swab to determine their genetic profile. The women were then put on bespoke diets that suited their DNA, for example low-fat or low-carbohydrate.
Those on the diet designed for their genes lost 2-3 times more weight than those on the ‘wrong’ diet, the study found.
The results suggested that the technology may have potential, but there’s a lot more research to be done before it starts changing the way we lose weight.
Take control of your weight
While some people may be genetically predisposed to gaining weight, there is no genetic reason why we all can’t be somewhere in the healthy weight range, said Dr Clare Collins, Professor of Nutrition and Dietetics at the University of Newcastle.
“People who make excuses aren’t successful,” she says. “The trick is to put the healthiest habits that you can live with on a long-term basis into practice and a healthy weight will find you.”
The good news is that the research on how to lose weight is tried and tested. No matter what your genetic profile, if you reduce your total daily calorie intake, you will lose some weight.
To lose 0.5-1kg a week, for example, you need to reduce your calories by 500-1,000 a day. That means cutting out 3,500-7,000 calories a week. This is because 1kg of body weight on the scales contains roughly 700g of actual fat. Each gram of fat is worth 10 calories.
Take charge of your weight with some lifestyle changes:
- Control your portion sizes
- Eat plenty of fruit and vegetables
- Cut down on alcohol
- Switching to low-fat dairy
- Use only lean meats
- Drink plenty of water
- Be more physically active
These are sure-fire ways to reduce your calorie intake, no matter what genes mum and dad gave you.