Are You Overweight Than Your Younger Sister? Birth Order Might Be Responsible For It

Posted: Aug 31 2015, 3:54am CDT | by , in News | Latest Science News


Are You Overweight than Your Younger Sister? Birth Order might be Responsible for it
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A Swedish study suggests that firstborn girls can be 40% obese than their later born sisters. Obesity might have something to do with birth order

First-born girls can be overweight or obese than their later-born sisters. That is what a new Swedish study suggests. 

Older girls can be 29% overweight and 40% more obese than their younger sisters, according to the study. Researchers came to this conclusion after looking at the data of more than 13,000 pairs of Swedish born sisters.

All the participants were at least 18 years old and pregnant. The information about their weights at the time of birth was obtained from Swedish National Birth Register. Their height and weight as being adults was taken during their first prenatal visit when they were about 10 to 12 weeks pregnant. 

At birth, first-borns were lighter than the second-born. But when they reached to adulthood, they were heavier than their younger sisters. They were slightly taller as well (1.2 mm).

In the first three months of pregnancy, first-born women also have a marginally higher Body Mass Index (BMI) than their younger sister. Though, the difference was very slim, 24.4 compared to 23.8.

The study was conducted to assess the impact of birth order on height and BMI of individuals. Some earlier studies also suggested that firstborn men were found heavier, taller and with a greater body mass index than their younger siblings. 

“Our study corroborates other large studies on men, as we showed that firstborn women have greater BMI and are more likely to be overweight or obese than their second born sisters.” Authors of the study write.

The study also suggests that firstborn may be at more high risk of health problems such as diabetes and high blood pressure in later their lives than their siblings. 

Having more siblings was linked with shorter heights in many previous studies but they never associated the number of children in a family with obesity or overweight.

“The steady reduction in family size may be a contributing factor to be observed increase in adult BMI worldwide.” Study concludes.

The study was published in Journal of Epidemiology & Community Health

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The Author

Hira Bashir covers daily affairs around the world.




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