Flying can take a toll on the body in many ways, but experts say there are simple nutrition rules travelers should follow to reduce common problems like bloating, dehydration, dry skin and fatigue. Air travel exposes travelers to changes in cabin humidity, pressure and oxygen levels that can affect overall comfort, with the dry cabin air being the biggest contributor to dehydration. In addition to thirst, dehydration can cause headaches, low energy, muscle cramps and dizziness. In more severe cases, it can also lead to confusion and fainting. Travelers are prone to making several mistakes that contribute to dehydration, experts say. Many…