Scientists in Aberdeen have found that people who carry a variant of the FTO gene that is linked to increased obesity - called the 'at risk' variant - eat more food than those who do not have the 'at risk' variant.
The Rowett Research Institute and the University of Aberdeen team studied 150 people from the North East of Scotland.
The volunteers were a normal cross section of the UK population aged between 21 and 60 - 20% of them were obese and 34% were overweight.
The researchers examined their food intake over seven days and took blood samples as well as other measurements which included checks of their physical fitness and how much energy they burned when they were resting.
They found that people with the variant of the FTO gene, on average, ate between 120 and 290 calories per day more than those who did not have the 'at risk' variant. Some examples of calories could be an apple which has between 60 and 80 calories, a chocolate bar which can have around 120 calories or a sandwich which may contain approximately 300 calories.
There was no association between the variants in the FTO gene and energy expenditure or physical fitness. Volunteers were also eating normally - not preferentially consuming any particular food group such as carbohydrates.
The findings are published online in the journal Obesity.
The link with obesity and the FTO gene was revealed last year by another group of UK scientists - although it was not known at that stage how it makes people fat.
Subsequent studies in mice have gone on to show that FTO is expressed in areas of the brain that are associated with the regulation of food intake.
Professor John Speakman, an author of the paper and Director of the Institute of Biological and Environmental Sciences at the University of Aberdeen, said of this latest study: "We have found the first hard evidence linking the 'at risk' variant of the gene with increased food intake in humans.
"Our data clearly suggests that people with this variant of the FTO gene may become fatter because they are driven to consume more food.
"Because this over consumption may be driven by their genes, it may be far harder for such people to control their intake than people who do not carry 'at risk' variants of food intake control genes.
"Greater consumption of food does not mean that people are being greedy."
Dr Alex Johnstone, a co-author of the paper, based at the Rowett Research Institute which will soon merge with the University of Aberdeen, added: "There are many factors involved in the development of obesity and this research suggests that the FTO gene contributes to differential food intake between volunteers."
Source: University of Aberdeen
Related stories:
Major genetic study identifies clearest link yet to obesity risk
Scientists have identified the most clear genetic link yet to obesity in the general population as part of a major study of diseases funded by the Wellcome Trust, the UK's largest medical research charity. People with two copies of a particular gene variant have a 70% higher risk of being obese than those with no copies.
H. Pylori bacteria may help prevent some esophageal cancers
Some bacteria may help protect against the development of a type of esophageal cancer, known as adenocarcinoma, according to a new review of the medical literature. These bacteria, which are called
Helicobacter pylori, live in the stomachs of humans.
Food for thought -- regulating energy supply to the brain during fasting
If the current financial climate has taught us anything, it's that a system where over-borrowing goes unchecked eventually ends in disaster. It turns out this rule applies as much to our bodies as it does to economics. Instead of cash, our body deals in energy borrowed from muscle and given to the brain.
Breakthrough in genetic map of wheat: scientists
Researchers on Thursday reported inroads in an ambitious project to map the genetic sequence of wheat, which ultimately could lead to the creation of more fertile and disease-resistant wheat strains.
Research team discovers brain pathway responsible for obesity
University of Wisconsin-Madison researchers, for the first time, have found a messaging system in the brain that directly affects food intake and body weight.
Scientists identify gene that may contribute to improved rice yield
A team of scientists, including Penn State Distinguished Professor of Biology Hong Ma, has identified a gene in rice that controls the size and weight of rice grains. The gene may prove to be useful for breeding high-yield rice and, thus, may benefit the vast number of people who rely on this staple food for survival. "Our work shows that it is possible to increase rice's yield by enhancing the expression of a particular gene," said Ma. The team's results will be published on 28 September 2008 in an early online edition of the journal
Nature Genetics, and in the November print issue of the journal.
Researchers find an essential gene for forming ears of corn
Cold Spring Harbor Laboratory (CSHL) professor David Jackson, Ph.D., and a team of plant geneticists have identified a gene essential in controlling development of the maize plant, commonly known in the United States as corn. The new research extends the growing biological understanding of how the different parts of maize arise--important information for a plant that is the most widely planted crop in the U.S. and a mainstay of the global food supply.
Bladder cancer detected via amplified gene in cells found in urine
Counting the copies of a specific gene in cells gathered from a urine sample may provide a simple, noninvasive way to detect bladder cancer, a team led by researchers at The University of Texas M. D. Anderson Cancer Center reports in the
Journal of the National Cancer Institute.
