Greek yogurt has become an increasingly popular low-calorie treat here in the U.S., as it is thicker and contains more protein than regular yogurt.   It is so much in demand that production has nearly tripled in the past 5 years.

But the new diet fad has a dark secret.  When Greek yogurt is strained, a thin, runny waste product known as acid whey is left over.   According to a new report from Modern Farmer, whey acid is extremely toxic to the environment.   It is actually now illegal to dump.   When this substance enters nearby streams and rivers, it robs the water of so much oxygen that fish and other aquatic life start to die off over large areas.

But the yogurt industry has remained relatively secretive on the issue.  The Modern Farmer report says a solution to the problem must be found as soon as possible, because the development of excess whey is not slowing down.