[Paleopsych] BH: Middle Age Spread 50% Genetic
checker at panix.com
Sun Jan 23 18:21:43 UTC 2005
Middle Age Spread 50% Genetic
Twin study shows why weight loss can be so hard for some
1/20/2005 12:40 PM
Genes account for about 50% of adult-onset weight change, the gain
that leads to so-called middle age spread.
So found researchers from Saint Louis University School of Public
Health in studying sets of identical and fraternal twins who served in
the military during the Vietnam War.
In total, principal investigator James Romeis and colleagues
studied nearly 8,000 male twins. In early adulthood, more than 75%
were of normal weight. Twenty years later, more than 55% were
overweight or obese.
Analyzing the data--identical twins share all their genes while
fraternal share half--the researchers found that about 50% of the
weight change was genetic. Environmental variables such as diet and
exercise accounted for the rest.
"We're not acknowledging the strength of genetic factors in our weight
loss strategies," says Romeis. "You've got this genetic thing working
against you that helps to explain why you're so heavy and why you may
fail at diets and weight loss programs."
For the participants in the study, weight gain appeared to hit at
"Your behavior changes at 30; you become more sedentary," says Romeis.
"At some point they tip into being overweight. Those who are
overweight tip into becoming obese. It's slow, incremental change. At
the same time, we didn't see much evidence that they lost weight
during the same time period."
The findings are reported in the journal Twin Research (read
More information about the paleopsych