When Kristina Thayer and more than a hundred other scientists set out to identify environmental pollutants that might increase the risk of obesity and diabetes, they weren’t thinking about Twinkies or a Quizno’s Classic Italian. They were thinking about such things as arsenic, cadmium, chlorinated organohalogens, bisphenol A and cigarette smoke. All of these pollutants, and others, had been implicated as possible factors in the obesity and diabetes epidemics. But the evidence came from a broad scattering of animal studies, in vitro tests and epidemiological studies. Nobody was sure what it all added up to, or which gaps in the research needed to be filled. Thayer will report the results of a broad survey of the research, which turned up some surprisingly strong connections, including evidence that some environmental pollutants are not only correlated with obesity—they are causing it.