Experts have warned that many mega-sized coffee and energy drinks are loaded with extra calories and sugar.
Ellen Schuster, a University of Missouri nutrition expert, said that people should be wary of extra calories and sugar in the quest for bigger, bolder drinks.
"The sheer size of new coffee and energy drinks increases consumers' potential for unhealthy calorie and sugar consumption," said Schuster.
Health experts at the Mayo Clinic noted that moderate consumption of coffee and other caffeinated beverages is unlikely to cause harm, but large quantities in excess of 500 mg, or more than four cups of coffee, can cause difficulty sleeping, irritability, restlessness, stomach problems and irregular heartbeat.
Especially of concern is caffeine consumption among children and adolescents.
"Energy and coffee beverages are subject to the same nutrition rules as other foods and drinks; it's all about moderation. Ideally, it's best to avoid drinking calories, because drinks leave you less full than solid foods.
"By eating calories in the form of high-calorie, high-sugar drinks, people crowd out other nutritious foods," he said.