trong>Narrator: This is Science Today. Simply put, healthy children learn better. Pediatrician Howard Taras of the University of California , San Diego School of Medicine, was recently commissioned by the National Coordinating Committee on School Health to review research studies to see what is really known about health and how it affects school performance.

Taras: The ones that we ended up writing about were obesity and how that affects school performance; physical activity, nutrition, asthma, sleep and how that affects school performance.

Narrator: Taras found the link between sleep and academic performance the most surprising.

Taras: I never realized just how much sleep seems to affect academic performance and most of those cases seem to be kids who may have large tonsils or adenoids obstructing a really good sleep at night. And there are a number of articles that show it's reversible so that kids will start improving academically once you correct that obstruction at night. So, it's nice when you have something that's reversible.

Narrator: For Science Today, I'm Larissa Branin.