The diets my friends swear by just never work for me ... .
The revelation from scientists that genetics play a major role in our ability to lose weight and get fit will comes as less of a shock to some of us.
"From my own experience I find exercise is pretty much the only thing that works with me," says Orla McCarthy. "I always tried diets but they just don't give me the results. Even when friends of mine recommend a certain diet, when I try it I just never see the same impact."
Even though Orla is a dietician based in Dublin by profession, she has always been aware that while healthy eating is a must, when it comes to staying in shape, for her it is gym or bust.
"I find I have to be in the gym three to four days a week to keep my shape," she says. "But I have friends who have never exercised or dieted and they look great."
Indeed, the latest research that proves your genetic make-up can hinder your efforts to become a gym bunny comes as little surprise to her.
"I agree 100pc both from a personal perspective and from a professional perspective," she says.
"However, while genetics obviously do play a role, I would always suggest striking a balance in terms of your diet and your exercise regime.
"Because if you are not willing to accept lifestyle changes you will not be able to maintain any achievements you have made in terms of weight loss or fitness."
With obesity levels in Ireland on the rise, Orla's work as a dietician reminds her on a daily basis of the growing need for people to exercise.
"I think people are a bit naive when it comes to their weight because they can fob things off by just thinking it is only genetics," she says.
"People think they don't eat enough to be fat, but when you come down to the nitty gritty most people use it as an excuse.
"We would generally say that only about 5pc of those who are overweight suffer because of their genetics.
"People just have to discover what works for them and build it into their lifestyle.
"But while people will always want quick fixes, regardless of your genetics I think getting fit and staying in shape requires commitment."
And it would seem that science isn't going to change that for some time to come.