Skip to content
My WebMD Sign In, Sign Up

Weight Loss & Diet Plans

Font Size

'Obesity' Gene at Work in Some People

But Gene Accounts for Obesity in Very Few People
WebMD Health News

Sept. 29, 2004 - An obesity gene does appear to pack on excess pounds in some people. But most of us can't point to our genetics as a reason for our tight jeans, researchers say.

Previous research has shown that people with abnormalities, or mutations, in certain genes are more likely to be obese. But these abnormal genes are rare and are found in only 2%-5% of obese people, according to new research.

In the study, German researchers focused on one of several genes that are linked to weight and metabolism -- the melanocortin-4 receptor gene, also called "MC4R." Mutations of the gene have been linked to obesity in mice and humans.

At least 34 mutations of this gene have been identified in various studies. Previous research has shown that some people with a mutated gene are overweight while others are not.

Johannes Hebebrand of Philipps University Marburg's child and adolescent psychiatry department, and colleagues studied 25 extremely obese people. They also looked at 181 of their relatives who were of normal weight or overweight, but not obese.

After screening for MC4R gene mutations, the researchers considered the participants' body mass index, or BMI, an indicator of body fat. You can calculate your BMI with WebMD's BMI calculator.

Hebebrand found that people with the gene mutations had a "significantly higher" current BMI than their relatives without the mutations.

The link was twice as strong in women as men.

Middle-aged women with the gene mutation weighed on average nearly 21 pounds more than those without the mutation. Among middle-aged men, the difference was smaller, almost a 9 pound difference between those with the mutation and those without.

The results are consistent with animal studies.

However, some normal-weight relatives also had one of these gene mutations. The researchers say that MCR4 is major gene for the development of obesity. However, given that not everyone with the gene was obese, they note that there are many factors at play in causing obesity.

The report appears in the October issue of the Journal of Medical Genetics.

Today on WebMD

Woman trying clothes / dress
Woman looking at reflection in mirror
Hot cup of coffee
woman shopping fresh produce
butter curl on knife
eating out healthy
Smiling woman, red hair
6-Week Challenges
Want to know more?
Chill Out and Charge Up Challenge – How to help your tribe de-stress and energize.
Spark Change Challenge - Ready for a healthy change? Get some major motivation.
I have read and agreed to WebMD's Privacy Policy.
Enter cell phone number
- -
Entering your cell phone number and pressing submit indicates you agree to receive text messages from WebMD related to this challenge. WebMD is utilizing a 3rd party vendor, CellTrust, to provide the messages. You can opt out at any time.
Standard text rates apply
What Girls Need To Know About Eating Disorders
teen squeezing into jeans
fitfor Teens

Special Sections