Researchers home in on obesity gene and offer explanation for overeating

November 02, 2003

An international team of researchers has identified the role of a gene which may explain why some people overeat and become obese.

Their research, published today in Public Library of Science Biology, shows that the gene GAD2 has an appetite stimulating role, and that one form of the gene is strongly associated with obese people.

While the researchers recognise that obesity is a result of the interactions of many genes and environmental factors, this is one of the first genes to be strongly touted as a candidate 'gene for obesity'.

GAD2, which sits on chromosome 10, acts by speeding up production of a neurotransmitter in the brain called GABA, or gamma-amino butyric acid. When GABA interacts with another molecule named neuropeptide Y in a specific area of the brain - the paraventricular nucleus of the hypothalamus - we are stimulated to eat.

The researchers behind this study believe that people who carry a more active form of the GAD2 gene build up a larger than normal quantity of GABA in the hypothalamus, and suggest that this over accumulation of GABA drives the stimulus to eat further than normal, and is thus a basis for explaining why obese people overeat.

Professor Philippe Froguel, senior author of the research, from Imperial College London, and Hammersmith Hospital, London, and who carried out the research while at the Institut Pasteur de Lille, France, said: "The discovery that this one gene plays a role in determining whether someone is likely to overeat could be crucial in understanding the continued rise in obesity rates around the world.

"Genetic factors alone can not explain the rapid rise in obesity rates, but they may provide clues to preventative and therapeutic approaches that will ease the health burden associated with obesity.

"Having identified this gene, it may be possible to develop a screening programme to identify those who may be at risk of becoming obese later in life, and take effective preventative measures."

The team compared genome-wide scans of 576 obese and 646 normal weight adults in France, from which they identified two alternative forms, or alleles, of the GAD2 gene.

One form of the gene was found to be protective against obesity, while another increased the risk of obesity. The normal weight group of French adults had a higher frequency of the protective form of the GAD2 gene. Obesity is three to five times less prevalent in France than in the USA.

In addition to the genome-wide scans, the obese patients also completed an eating habits questionnaire, measuring dietary restraint, disinhibition and perceived hunger. The results showed that those carrying the GAD2 allele that increases the risk of obesity were significantly more likely to reveal an inability to control their food intake, and perceive high levels of hunger.

Authors of this research are based at Imperial College London, Hammersmith Hospital, London, the Institut Pasteur de Lille, France, the University of Washington, USA, Paul Brousse Hospital, and Paris VI University, France.
-end-
Notes to editors:
1. GAD2 on Chromosome 10p12 is a Candidate Gene for Human Obesity, Public Library of Science, 3 November 2003. Website:
http://www.plosbiology.org/
2. Consistently rated in the top three UK university institutions, Imperial College London is a world leading science-based university whose reputation for excellence in teaching and research attracts students (10,000) and staff (5,000) of the highest international quality. Innovative research at the College explores the interface between science, medicine, engineering and management and delivers practical solutions that enhance the quality of life and the environment - underpinned by a dynamic enterprise culture. Website: www.imperial.ac.uk.

Imperial College London

Related Obesity Articles from Brightsurf:

11 years of data add to the evidence for using testosterone therapy to treat obesity, including as an alternative to obesity surgery
New research covering 11 years of data presented at this year's European and International Congress on Obesity (ECOICO 2020) show that, in obese men suffering from hypogonadism (low testosterone), treatment with testosterone injections lowers their weight and improves a wide range of other metabolic parameters.

Overlap between immunology of COVID-19 and obesity could explain the increased risk of death in people living with obesity, and also older patients
Data presented in a special COVID-19 session at the European and International Congress on Obesity (ECOICO 2020) suggests that there are overlaps between the immunological disturbances found in both COVID-19 disease and patients with obesity, which could explain the increased disease severity and mortality risk faced by obese patients, and also elderly patients, who are infected by the SARS-CoV-2 virus that causes COVID-19 disease.

New obesity guideline: Address root causes as foundation of obesity management
besity management should focus on outcomes that patients consider to be important, not weight loss alone, and include a holistic approach that addresses the root causes of obesity, according to a new clinical practice guideline published in CMAJ (Canadian Medical Association Journal) http://www.cmaj.ca/lookup/doi/10.1503/cmaj.191707.

Changing the debate around obesity
The UK's National Health Service (NHS) needs to do more to address the ingrained stigma and discrimination faced by people with obesity, says a leading health psychologist.

Study links longer exposure to obesity and earlier development of obesity to increased risk of type 2 diabetes
Cumulative exposure to obesity could be at least as important as actually being obese in terms of risk of developing type 2 diabetes (T2D), concludes new research published in Diabetologia (the journal of the European Association for the Study of Diabetes [EASD]).

How much do obesity and addictions overlap?
A large analysis of personality studies has found that people with obesity behave somewhat like people with addictions to alcohol or drugs.

Should obesity be recognized as a disease?
With obesity now affecting almost a third (29%) of the population in England, and expected to rise to 35% by 2030, should we now recognize it as a disease?

Is obesity associated with risk of pediatric MS?
A single-center study of 453 children in Germany with multiple sclerosis (MS) investigated the association of obesity with pediatric MS risk and with the response of first-line therapy in children with MS.

Women with obesity prior to conception are more likely to have children with obesity
A systematic review and meta-analysis identified significantly increased odds of child obesity when mothers have obesity before conception, according to a study published June 11, 2019 in the open-access journal PLOS Medicine by Nicola Heslehurst of Newcastle University in the UK, and colleagues.

Obesity medicine association announces major updates to its adult obesity algorithm
The Obesity Medicine Association (OMA) announced the immediate availability of the 2019 OMA Adult Obesity Algorithm, with new information for clinicians including the relationship between Obesity and Cardiovascular Disease, Diabetes Mellitus, Dyslipidemia, and Cancer; information on investigational Anti-Obesity Pharmacotherapy; treatments for Lipodystrophy; and Pharmacokinetics and Obesity.

Read More: Obesity News and Obesity Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.