Energy drinks: popular energy drinks contain green tea extract and caffeine. do these energy drinks you lose weight by increasing your metabolism? researchers at a medical school designed an experiment to determine the effects of green tea and caffeine on energy metabolism in healthy, lean, young adults. researchers randomly assigned participants to 2 treatments. one group drank formula a, a beverage with green tea and caffeine. the other group drank formula b, a beverage with none of these ingredients but colored to look like formula a. the beverages were blinded at the production site, so the experiment was double-blind. the researchers chilled the beverages to 6°c. participants drank the beverages at the same time each day for three days. during the 3 days of the experiment, the researchers feed each participant the same diet. on the third day participants spent 24 hours in a calorimeter chamber to measure their energy metabolism. the medical journal obesity published the results in 2007. what is the purpose of double-blinding?