Yes — you can absolutely bring your own food through airport security, on domestic and international flights alike. Solid foods pass through the X-ray without any issue in your carry-on or personal item: sandwiches, fruit, crackers, nuts, chocolate, protein bars and baked goods are all fine. There is no size or quantity limit for solid food, which is why packing your own snacks is the simplest way to avoid overpriced airport food and unpredictable airline meals.

The one trap is the liquids rule. Foods that are spreadable, pourable or gel-like — yogurt, hummus, peanut butter, jam, soup, dips, smoothies — count as liquids and must follow the 100 ml (3.4 oz) rule: small containers inside a single transparent resealable bag. That pot of yogurt and that jar of peanut butter are the two items security pulls most often. If you are unsure whether something counts as a liquid, assume it does and pack accordingly.

Homemade food and open snacks are allowed too. A sandwich in a reusable container, last night's leftovers, or an open bag of trail mix will all clear security as long as they are solid. Pack them in leak-proof containers or clear resealable bags: it keeps your bag clean and speeds up screening, which is even more valuable as airport security operations keep evolving and queues stay long.

The real restriction is not security — it is customs at your destination. While you can eat anything on the plane, most countries ban bringing fresh fruit, vegetables, meat and seeds off the aircraft to protect against agricultural pests. Finish that apple or ham sandwich before landing, or declare it and use the amnesty bins in arrivals. Failing to declare can mean heavy fines or losing trusted-traveler status, so plan your snack timeline around the flight, not the trip.

A few cabin rules worth knowing: you may eat your own food freely, but you may not drink your own alcohol on board — aviation regulations require all alcohol to be served by the crew so they can monitor intoxication. And be a considerate neighbor: avoid pungent foods like tuna, strong garlic or durian in the enclosed cabin. Your seatmates will remember you long after the meal is gone.

The best flight-food kit is simple: sandwiches or wraps, nuts and dried fruit, a protein bar, and an empty water bottle to fill after security. On routes vulnerable to weather disruptions, where tarmac delays and missed meal services are common, that little stash turns a miserable delay into a manageable one. Pack it the night before and you will never depend on the airline's catering again.