4 of 29

You skimp on sleep

Think it's a good idea to get up at 5 a.m. and hit the gym? Not if you should be sleeping instead, says Gary Rogg, MD, a primary care physician and assistant professor at Montefiore Medical Center in the Bronx, N.Y. Studies have consistently shown that people need at least seven hours of sleep a night for optimal health, and short sleep has been associated with a host of health problems, including high blood pressure, depression, diabetes, and a reduced immune response to vaccines.

Next: You lack supplement savvy