Year You're Born Linked to Obesity
Lifestyle and diet are two primary factors involved in weight gain, but new research suggests that even the year you were born is linked to obesity risk.
Previous research has shown that a variant in what is called the FTO gene can lead to obesity. And with this latest study, researchers say that the FTO variant largely depends on birth year, with those born in later years exhibiting a far stronger correlation between gene variant and obesity. Participants born in earlier years, on the other hand, demonstrated no such correlation between the two factors.
"Looking at participants in the Framingham Heart Study, we found that the correlation between the best known obesity-associated gene variant and body mass index increased significantly as the year of birth of participants increased," lead author James Niels Rosenquist said in a statement. "These results - to our knowledge the first of their kind - suggest that this and perhaps other correlations between gene variants and physical traits may very significantly depending on when individuals were born, even for those born into the same families."
The researchers analyzed data from 1971-2008 from the Framingham study, which involved participants aged 27 to 63. During their research, they measured the subjects' body mass index (BMI) eight times, finding that the previously reported association between a specific FTO variant and BMI was seen, on average, only in participants born in later years.
The year in question was 1942, with those born before this time showing no correlation between the obesity-risk variant and BMI, while the correlation was twice as strong in participants born after 1942. The researchers surmise that humans' increased reliance on technology rather than physical labor, and the increased popularity of fast foods, all which occurred during the post-World War II era, are to blame.
"Our results underscore the importance of interpreting any genetic studies with a grain of salt and leave open the possibility that new genetic risk factors may be seen in the future due to different genetically-driven responses to our ever-changing environment," added Rosenquist.
The findings were reported in the journal PNAS.
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