If you think America's obesity epidemic will pass you by because you are young and fit now, think again. In the past 30 years, the portion of the population that is obese has risen from 15 percent to 33 percent. Now the Centers for Disease Control and Prevention predicts that more than 42 percent of people will be obese by 2030 – not just overweight, but clinically obese, with a body mass index of more than 30. (A healthy BMI for men is around 19 or 20.) And scientists can only speculate about the percentage of people who will be overweight.
This new statistic, while frightening, isn't a surprise to obesity experts who have watched and forecasted America's growing levels of fatness for decades. And now experts are scrambling to understand why. Most blame the epidemic on a variety of factors that can include everything from more chemicals in personal-care products, furniture, and food to the lack of sidewalks on city streets and a proliferation of elevators in buildings. Among many leading authorities, a contentious debate exists over whether it's the calories or the carbs in food that cause people, including those who work out every day, to pack on the pounds. Here, we examine five different perspectives from some of the country's leading obesity experts.
Toxins cause weight gain.
Developmental biologist at the University of California at Irvine
Bruce Blumberg is on the trail of what he believes to be the missing piece of the obesity-epidemic puzzle: obesogens, or chemicals in food, packaging, personal-care products, furniture, paint, and hundreds of other common household items that interfere with our body's hormone production and cause weight gain.
Blumberg admits that no one knows just how big a role obesogens play in the obesity epidemic – "Is it one percent? Is it 90 percent?" – but his landmark work on one chemical compound suggests that toxins are worth worrying about in the obesity equation. Blumberg found that mice exposed to tributyltin (TBT), a chemical found in some vinyl, paint, wood finish, wood pulp, disposable diapers, and a slew of other products – and even the pups of mice exposed to TBT – get fat eating the same number of calories as their TBT-free peers. For obvious reasons, humans haven't been dosed in the lab, but two diabetes drugs, Actos and Avandia, activate the same fat-depositing gene as TBT and cause the same effect: weight gain. "How can you not connect the dots?" Blumberg asks. And TBT isn't the only troublesome toxin. Chemicals in colognes, moisturizers, and a range of other personal-care products, as well as those in Teflon and bags of microwavable popcorn, and the most insidious – bisphenol A (BPA) – all cause problems, he says. What this means, he adds, is that we're a population-wide experiment in progress.
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Blumberg believes the FDA should ban chemicals like BPA outright. He's also involved in a "green chemistry" movement among scientists to develop safe chemicals for household and personal-care products. "The market will sweep out the obesogenic and endocrine-disrupting stuff because there will be alternatives," he says.