There's no evidence that dairy or calcium consumption promotes weight loss, says a U.S. study that challenges claims that dairy products help people shed pounds.

Researchers from the University of North Carolina at Asheville and the Physicians Committee for Responsible Medicine analyzed 49 clinical trials conducted from 1966 to 2007, United Press International reported. The studies examined how milk, dairy products or calcium intake affected body weight and body mass index.

The review authors found that neither dairy products nor calcium supplements helped people lose weight. Of the 49 studies included in the review, 41 showed no effect, five showed weight loss, two showed weight gain, and one showed a lower rate of weight gain.

"Our findings demonstrate that increasing dairy product intake does not consistently result in weight or fat loss and may actually have the opposite effect," the review authors said in a prepared statement, UPI reported.

The findings were published in the journal Nutrition Reviews.