THE QUESTION Sodas, sports drinks, energy drinks and the like are the beverages of choice for many youths. Might consuming such sweetened and often highly caffeinated drinks affect their behavior?

THIS STUDY involved 1,649 middle school students (average age, 12), who were asked about their daily consumption of any drink sweetened with sugar, high-fructose corn syrup or other caloric sweeteners.

Most students drank two or more types of sweetened drinks a day, more often soda but including fruit drinks, sweetened coffee, flavored milk and sports drinks; about 15 percent of the students drank energy drinks daily.

On a standardized scale rating traits of inattention and hyperactivity (being restless, fidgeting, having difficulty concentrating), 85 percent of the students ranked in the normal range.

As daily consumption of sweetened beverages increased, so did risk for inattentive and hyperactive behavior, rising 14 percent for each additional drink they had. Students who regularly consumed energy drinks were 66 percent more likely than those who didn’t drink them to be inattentive or hyperactive, regardless of how many other sweetened beverages they drank.

WHO MAY BE AFFECTED? Young people. A government survey found that 63 percent of high school students drink sweetened beverages daily, with 33 percent drinking two or more a day. Although some of these drinks also contain caffeine, the caffeine content of energy drinks generally is considerably higher than other sweetened drinks. Both sugar and caffeine can have a stimulating effect, boosting energy and alertness, but too much can cause problems.

CAVEATS Data on drink consumption came from the students’ responses on a questionnaire; the data did not contain details on specific brands or the exact amount consumed. Behavioral data came from responses on a standardized mental health questionnaire that researchers then used to rate each child. For participating in the study, the students received a water bottle. The authors noted that youths with hyperactive/inattentive symptoms “may be drawn to consuming energy drinks for psychological or physiological reasons.”

FIND THIS STUDY Feb. 8 online issue of the journal Academic Pediatrics (journals.elsevier.com/academic-pediatrics; check under “Recent Articles,”

LEARN MORE ABOUT energy drinks at nccih.nih.gov/health. Learn about how caffeine affects youths at www.kidshealth.org (enter parents’ site).

The research described in Quick Study comes from credible, peer-reviewed journals. Nonetheless, conclusive evidence about a treatment's effectiveness is rarely found in a single study. Anyone considering changing or beginning treatment of any kind should consult with a physician.