04/11/2011 10:27 GMT | Updated 03/01/2012 05:12 GMT

The Fat Gene? Do Yourself a Favour and Forget About It

Do you think that you have the "fat gene" that makes you more likely to gain weight?

I know for some people who are overweight, it can be some comfort to know that their genes predispose them to gain weight. It gives them a reason and some meaning for why they struggle to stay slim.

Indeed, when we see a family where every member is overweight, there can really be only two explanations:

1. Their genes predispose them to being overweight

2. The family has particular patterns of behaviour that make it more likely they will be overweight.

The reality, I suspect is probably a combination of the two. But the point is, while you may get some comfort from knowing that your genes contributed to your predicament, it is not going to change anything.

As we know, your genes are not your destiny. Being predisposed to being overweight doesn't necessarily make you overweight. Furthermore, the worrying increases in rates of obesity in our society over the last few decades can clearly not be blamed on genes.

No, the fact is despite "fat genes", you only gain weight, when you eat too much. And there are two factors that contribute to eating too much that have nothing to do with genes. These being environment and behaviour patterns.

One of the clients who I work with came from a family where everyone was thin. Not only were they thin, but they were the sort of family who seemed to be able to eat a lot and still not gain weight. This is what made it all the more frustrating for this client when she started gaining weight in her late forties.

In the meantime her sister who was slightly older than her, remained slim. How had my client gained weight while her sister hadn't? Because bad habits had crept in. She was eating slightly more every day and over time that had eventually translated into gaining weight.

Working with me, she retrained her eating and exercise habits and lost the weight. But an interesting thing happened. Her sister had gone through a difficult period in her life and started gaining weight. This was at the same time as my client was losing weight. Their roles were reversing.

Here were two people who may have had a (positive) genetic component to their weight, but who were clearly gaining and losing weight purely due to changes in their environment and their behaviour.

To put it simply, when they ate more, they gained weight.

And so let's say you're unlucky enough that your genes make it more likely that you gain weight. What's the solution? The solution is the same whether you have "bad" genes or not. You need to make changes to what and how much you eat, and you need to get more active. But most importantly of all, these changes need to become part of your lifestyle.

"Fat gene" or not, the power is in your hands.