Coffee, energy drinkers beware: Many mega-sized drinks loaded with sugar, nutrition expert says

"The sheer size of new coffee and energy drinks increases consumers' potential for unhealthy calorie and sugar consumption," said Schuster, state specialist for MU Extension and the College of Human Environmental Sciences. "A 'Trenta'-sized Starbuck's lemonade could include 21 teaspoons of sugar -- much more than should be consumed at one time, or in one day."

Excess sugar is common in many prepared beverages. According to the U.S. Department of Health and Human Services, people who consume drinks with added sugars consume more total calories, and studies have found that drinking sweetened beverages is related to weight gain.

Health experts at the Mayo Clinic note 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," Schuster said. "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. However, like any indulgence, it's fine to order a 'Trenta' drink as an occasional treat."