Why is it so hard to lose weight -- and keep it off? The doctors uncover triggers for overeating and learn about a fat that could make us thinner.
Shalin visits a sleep clinic to cure his snoring, Renee helps a sleep-deprived teen, and Sandro asks if eight hours really is the magic number.
While Shalin examines why allergies are on the rise, Sandro meets researchers close to a cure. Renee reports on an outbreak of "thunderstorm asthma."
Sandro explores the link between food and mood, Shalin gets tested for lactose intolerance, and Renee reveals how sports drinks stack up against water.
Sandro volunteers for a nerve-wracking experiment. Renee boards the "brain bus," a mobile lab with a mind-bending approach to treating chronic pain.
Shalin weighs the pros and cons of getting his genome sequenced, and Renee discovers how two mice help treat a boy's autoimmune genetic condition.
While Shalin and friends sit down for a boozy lunchtime experiment, Renee learns how binge drinking could change teenagers' brains.
Sandro tries a seven-minute workout, Shalin pits his heart against an elite athlete, and Renee explores how exercise boosts mental health.
After testing two different diets, Shalin learns which foods help gut health. Renee reveals a surprisingly effective treatment for intestinal disease.
The doctors demonstrate how to prevent colds, discuss which home remedies really work and investigate hopes for a universal flu vaccine.
Renee explores the connection between scent and memory, Sandro busts common myths about eyesight, and Shalin puts his ears to the test.
The doctors break down the science of sex, from birth control options and the history of condoms to a promising new treatment for infertility.