THURSDAY, May 23 (HealthDay News) -- People who eat at fast-food restaurants are consuming significantly more calories than they realize -- and teens are the worst offenders, a new study found.

THURSDAY, May 23 (HealthDay News) -- A modified version of the polio virus might one day help fight brain tumors, preliminary research suggests.

THURSDAY, May 23 (HealthDay News) -- Glucosamine supplements that millions of Americans take to help treat hip and knee osteoarthritis may have an unexpected side effect: They may increase risk for developing glaucoma, a small new study of older adults suggests.

THURSDAY, May 23 (HealthDay News) -- A shortage of a critical tuberculosis drug has hampered the efforts of health departments across the United States to contain the spread of the highly infectious lung disease, federal officials report.

THURSDAY, May 23 (HealthDay News) -- Heavy consumption of diet soda can damage teeth as badly as methamphetamine or crack cocaine, a new study contends.

THURSDAY, May 23 (HealthDay News) -- Statins are proven drugs taken by millions to lower their cholesterol, but the medications also could hamper heart patients' ability to improve their cardiovascular health through exercise, researchers say.

THURSDAY, May 23 (HealthDay News) -- Mild to moderate iodine deficiency during pregnancy may have a negative long-term impact on children's brain development, British researchers report.

THURSDAY, May 23 (HealthDay News) -- Schools should ensure that kids get at least one hour of physical activity each day to support their health and boost performance in school, according to a new report.

Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:

THURSDAY, May 23 (HealthDay News) -- While some fast-food chains are required to provide calorie and other nutritional information to help customers make informed choices, kids who eat fast food at least twice a week are 50 percent less likely to use this information than kids who eat fast food less often, according to a new U.S. study.