I read a rather startling article in last weeks Science News. Here is the first half. The rest is available on the Science News web site. 

Waistline Worry: Common chemicals might boost obesity

Aimee Cunningham

A family of chemicals implicated in testosterone declines may also be contributing to recent spikes in obesity and diabetes, according to a new study.

Phthalates show up in a wide range of manufactured items, from cosmetics to vinyl flooring to medical devices and drug coatings. With people's extensive exposure to phthalates, the chemicals' breakdown products, or metabolites, appear in the urine of more than 75 percent of the U.S. population.

Previous research had shown that phthalates decrease testosterone concentrations and harm reproductive development in male animals (SN: 4/3/99, p. 213: http://www.sciencenews.org/sn_arc99/4_3_99/fob3.htm). Effects have also been found in people. Exposure to phthalates in the womb has been linked to genital changes in male infants (SN: 6/4/05, p. 355: http://www.sciencenews.org/articles/20050604/fob1.asp), while a study in adult men found an association between the chemicals and sperm abnormalities (SN: 5/31/03, p. 339: http://www.sciencenews.org/20030531/fob1.asp).

In men, low testosterone can lead to abdominal obesity and insulin resistance—conditions that are precursors of heart disease and type 2 diabetes, notes Richard W. Stahlhut, a research physician at the University of Rochester (N.Y.) School of Medicine and Dentistry. "If phthalates are affecting sperm counts and testosterone levels, then you would expect these guys would get abdominal obesity and insulin resistance," he says.

[...]

The researchers found that the men with abdominal obesity, insulin resistance, or both were more likely than the other men to have high concentrations of phthalate metabolites in their urine. The team reports its results online and in an upcoming Environmental Health Perspectives.