Beer bellies - the bare facts
17 Jan 2003
Last week, Italian scientists announced they'd found a gene variation that predisposed certain men to getting a flabby stomach, or "beer belly". So are some men simply destined to become fat?
You won't be surprised to hear that genes are only part of a disturbing trend toward obesity in our society and across the world.
While there is increasing evidence that men, like women, are genetically programmed to assume certain body shapes, it is environmental factors - such as eating too much unhealthy food - that really make people pile on the pounds.
The Italian researchers from the University of Naples tested 1,000 men for a certain genetic variant, known as DD. They found 40 per cent of the men had the DD genotype and of these, 52 per cent were overweight. Of those people without the genotype, 44 per cent were overweight.
Not a huge difference and not an entirely new discovery either. Back in 1995, a Canadian study found much the same thing by focusing on a different gene. One of the experts in this field, Thorkild Sorensen from the Institute of Preventative Medicine at Copenhagen University Hospital concluded, "The genes determine who's hit by obesity, and how hard."
But as the Director of Policy and Public Affairs for the International Obesity TaskForce, Neville Rigby, explains - it's not that simple. "Many genes interact, it is hard to pinpoint a single gene that causes obesity," he says. He agrees that certain people are predisposed to weight gain and wider waistlines but insists, "It is a combination of genes and the environment."
As both Mr Rigby and Brigid McKevith, a nutritional scientist at the British Nutrition Foundation, point out, there has always been this "beer belly gene" but it is only in recent years that the world has seen a huge increase in obesity.
More than 30 per cent of the US adult population is obese. In the UK, the figure is only slightly lower at 21 per cent. And this trend is being repeated all over the world. Even countries previously untroubled by obesity are getting fatter. A recent study showed that 27 per cent of Italian children were overweight or obese.
Piling on the pounds
So why are we getting fatter? Intriguingly, Neville Rigby says there is growing evidence that many people have been programmed in the womb to become fat. A famous Dutch study found that the offspring of women made to go hungry during the war when they were pregnant are now noticeably fatter than children born nearby where food was more plentiful.
The effect of rations on the height of war children, now adults, is well known but Mr Rigby says the lack of nutrients available while a foetus develops alters the way it grows and so makes the child and adult more disposed to gaining weight. He calls it the legacy effect of hunger.
Plus, of course, our modern diet is notoriously unhealthy. "We have an environment of plenty, an excess of fat and sugar, a plethora of junk food - high-calorie, low-nutrient foods - and, of course, a lack of activity," says Mr Rigby.
Ms McKevith is, unsurprisingly, in agreement, "I know people get sick to death of people like me saying that you should eat more fruit and vegetables but they are low fat and leave less room for fattier, more unhealthy food."
A fatter world population is a huge issue, and Mr Rigby says there is a whole raft of problems associated with obesity. "The most common is type 2 diabetes - we are now seeing examples of it in children, something that has never been seen before. Then there is heart disease, increased risk of cancers - breast, kidney, colon - osteoporosis." The list goes on and on and on.
The worldwide diet
So what's to be done? The International Obesity TaskForce is dedicated to reducing levels of obesity in society and is working with the World Health Organization and governments around the world to push home the importance of diet and activity. Mr Rigby tells us that a new report, due in March this year, is expected to make some controversial recommendations. However, he declined to be more specific.
In the US, which has possibly the greatest problem with obesity, the government is putting pressure on the food industry to look at providing healthier products for the good of the population.
Ms McKevith has some practical advice. "You have to make small changes, if you try to do all things at once you will fail." She stresses that you can't talk about changes in diet without talking about changes in activity as well.
"We also try to turn people off the idea of good food or bad food. As soon as you say you can't have chocolate, that's what people want," she says. "There is no such thing as good or bad food, it's just the quantity that you have of it that matters."
And that means the whole world needs to cut down on junk food, sweets and snacks, and start eating more fruit and vegetables. You may have been born with genes that will help you to get big round the middle - but you have to put the fat there in the first place.
International Obesity TaskForce
British Nutrition Foundation