The speakers at the workshop discussed evidence from both studies with animal models and human epidemiological studies that exposure to environmental chemicals is linked both to weight gain and to glucose tolerance, insulin sensitivity, inflammation, and other aspects of the metabolic syndrome. In addition to conventional environmental chemical exposures, this workshop also included one panel to discuss the potential role of other exposures, including sugar, artificial sweeteners, and antibiotics, in aiding or causing obesity. The participants also examined possible biological pathways and mechanisms underlying the potential linkages. This publication summarizes the presentations and discussions from the workshop.