No expert ever seriously claimed that environmental contamination is the sole cause of the obesity pandemic. It's understood to be a multifactorial problem.
While this isn't really proven yet I do suspect that widespread ingestion of endocrine disruptor chemicals such as phthalates (plastic softeners) is one of several root causes. Average phthalate levels have been rising for years, we know they reduce testosterone, and we also have data to show that average testosterone levels have been falling. Low T causes growth of adipose tissue.
While this isn't really proven yet I do suspect that widespread ingestion of endocrine disruptor chemicals such as phthalates (plastic softeners) is one of several root causes. Average phthalate levels have been rising for years, we know they reduce testosterone, and we also have data to show that average testosterone levels have been falling. Low T causes growth of adipose tissue.