Evolving Obesity Beyond Our Own Genes
“Our genes certainly haven’t changed as quickly as obesity has increased.” That logic fragment frequently surfaces to justify blaming people living with obesity for their condition. Yet in the population, we see evolving obesity prevalence that is entrenched at levels well above historic levels.
The obvious explanation is that our genetic inheritance sets the table for obesity, but our environment serves the meal that creates the problem. And certainly changes — in the quality of our food supply, in patterns of physical activity required by jobs, schools, and community infrastructure, and in stresses imposed upon us — have all played a role.
But some scientists are proposing that we consider the evolution beyond our own genes as a factor in obesity trends that are becoming so deeply entrenched. Jameson Voss, Juan Leon, Nikhil Dhurandhar, and Frank Robb are proposing in a new commentary that changes in the human microbiome represent a genetic adaption fueling obesity trends.
Likewise, Edward Archer has proposed that the growing prevalence of childhood obesity is the result of nongenetic evolution connected to maternal health. He describes a “metabolic tipping point” between mothers and children in the late 20th century that made the present epidemic of obesity inevitable.
These concepts provide useful ways for thinking about the roots of obesity. Individual choices certainly matter for making one’s health better or worse. But the problem is much larger than one individual can bear or be expected to change. Understanding the scope and origins of the problem is one step toward tools for prevention and medical care that will reverse it.
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