An article in the HealthDay News says that a new study suggests that exposure to a class of chemicals commonly found in soap and plastics could be fueling the obesity epidemic by contributing to abdominal obesity and insulin resistance in men

The chemicals, known as phthalates, have already been implicated in male reproductive problems including low sperm counts and low testosterone levels. However, it's too soon to know whether they are actually causing these health problems, cautioned the researchers and others.
Phthalates have been widely used for more than half a century in everything from paint to time-released medicines, but only recently have they become a topic of concern. Animal studies show that phthalates decrease testosterone levels while human studies have found that phthalates are associated with poor sperm quality in men.

This study follows up on other studies that correlated abnormal sperm counts and low testosterone levels with phthalates. Men with low testosterone levels develop abdominal obesity and insulin resistance, so these authors speculated that phthalates might be behind the depressed testosterone levels.