You always pack an extra pair of underwear in your carry-on, so why not some extra healthy snacks too?
"We often underestimate the amount of time a trip can take," Platkin writes on his site. "A two-hour flight could mean four or five hours of travel."
Although liquids are restricted, most foods can be taken through security, according to the Transportation Security Administration. Platkin recommends dry cereal like shredded wheat, energy bars or cold cut sandwiches. Raw fruits and vegetables are also easy to pack and carry onboard.