Ffects 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 3rd day participants spent 24 hours in a calorimeter chamber to measure their energy metabolism. The medical journal Obesity published the results in 2007. Which of the following is an example of direct control used in this experiment? Check all that apply. Drinking the beverages at the same time each dayMixing green tea and caffeine Feeding each participant the same diet