Moms-to-be could affect child’s risk for obesity
An obesity researcher has put forth a new theory that it’s not how much we eat or how little we exercise that makes us so overweight.
While both are important elements, Edward Archer, an obesity theorist and postdoctoral research fellow at the Nutrition Obesity Research Center at the University of Alabama at Birmingham, contends that most people are obese due to a combination of their mother’s body composition and her activity level while she was pregnant.
Sounds crazy, and it is controversial, but hear him out.
Archer said that most obesity is caused by what’s known as nongenetic evolution. This means you didn’t inherit your tendency to be obese genetically, the way you got your hair color or your height. But rather through other means. And that’s where your mom’s body composition and activity level come in.
Before modern conveniences removed the need for most people to work long hours in fields or factories, much of the
food a pregnant woman consumed went to fuel her own body. Sure, nature made sure her growing baby got the nutrients it needed, but everything, usually, was kept in balance.
Fast-forward to the 1950s, when Americans started becoming more sedentary. Thanks to modern, labor-saving devices, the average American woman burned almost 2,000 fewer calories per week in 2010 than her counterparts did in 1965. Yet she eats just as much, if not more.
Since her body uses less energy than did her predecessor’s, it shuttles the extra calories, in the form of glucose, to her developing fetus.
The mother-child energy balance is thrown out of kilter.
“Exercise is incredibly important for pregnant women, yet between 75 percent and 95 percent of U.S. adults, including women who are pregnant or are trying to get pregnant, don’t meet the minimum federal guidelines for physical activity,” Archer said. “And 20 percent of pregnant women today watch six or more hours of TV a day.”
As Archer explained in the journal Mayo Clinic Proceedings, this extra energy causes changes in the baby’s metabolism, increasing the number and size of the fetus’ fat cells. So these babies grow a little bit larger and a little bit fatter than those of the previous generation. And since the child’s mother — and likely the father, too — is inactive, the child will grow up without an adult modeling the benefits of physical activity.
The result is a child, and later an adult, who is more likely to be inactive and become overweight, or even obese.
“Initially, the changes are minor, but with each generation, the effect snowballs until it reached a tipping point in the ’70s and ’80s, and we have an obesity epidemic,” Archer said.
A Texas obesity researcher questions Archer’s theory.
“Everyone is different genetically, but not every genetic variable can be expressed,” said Anthony G. Comuzzie, co-director of the TOPS Nutrition and Obesity Research Center at the Texas Biomedical Research Institute. “Genes don’t exist in a vacuum, so it’s only when mothers suddenly have all this food available that the child’s propensity to become heavier can arise. So there is a genetic basis to the obesity epidemic.”
In what Comuzzie called a “wrinkle,” this over-abundance of food also can cause changes in DNA that can make the child more likely to become obese later in life.
Yes, living a sedentary life and eating a diet of fast food and other high-calorie stuff doesn’t help. But children born to inactive, often overweight mothers already have the cards stacked against them in the form of increased risk for obesity, type 2 diabetes, cancer and a host of other problems.
Archer makes a point of not blaming mothers, however.
“In fact, mothers are the cure,” he said. “Especially active mothers.”
His prescription is for women to be as active as possible before, during and after their pregnancy. Not only will this improve her own health and the health of her unborn child, but if the baby is a girl, this activity will impact the metabolism of the eggs that are developing in the fetus, too.
Archer says that by staying active, mothers could put a halt to the obesity epidemic in a single generation.
But what about those who have been overweight their whole lives? Archer says that, first, the rest of us need to stop blaming them because it’s not a result of their moral failings.
“Face it, more than 90 percent of people are unable to lose weight and keep it off,” he explained. “But that doesn’t mean they shouldn’t exercise and eat well. They just need to understand that they’re doing that to improve their health, not to lose weight.”