As airlines economize by eliminating or reducing meal service on flights, many people choose to bring their own snacks and drinks. While a limited amount of food and beverages for consumption on the flight may be brought onboard, the quantity is subject to guidelines set by both United Airlines and the U.S. Department of Homeland Security's Transportation Security Administration division.
All liquids carried through the security checkpoint are subject to limitations set by the Transportation Security Administration. Their guidelines state that all liquids and gels must fit in 3.4 ounce bottles that are carried inside one 1-quart bag and must be pulled out of your luggage for screening. Certain food items - including salad dressing, soup and pudding - are considered liquids and must adhere to the guidelines. If you wish to bring your own beverages onboard, it is simpler (though more expensive) to purchase drinks after clearing security.
Food may be brought onboard in any quantity if it fits within the carry-on baggage guidelines, as set by the airline. United Airlines also allows an additional limited amount of food or beverages purchased at the airport to be brought onto their planes. Food is allowed in your checked baggage, so this may be a good way to transport that special sauce for a family dinner on your trip home. Many international flights may have prohibitions on fresh vegetables, fruit or nuts; this is often determined by the destination country. In many cases, a small quantity to be consumed on the plane will be allowed, especially if prepared and packaged, rather than whole.
Things to Consider
Be considerate of your fellow passengers. While there are no prohibitions against strongly-scented foods, a delicious curry may not be appropriate for a crowded flight. Peanuts, or foods containing peanuts, may be prohibited if one of the passengers notifies the flight crew of an allergy. Knives, with the exception of plastic and rounded butter knives, are not allowed on a flight, so make sure your food is pre-cut.
The Transportation Security Administration and United Airlines do make exceptions for people with special needs. Supplies for babies, including formula, food and breast milk are exempt from the 3-1-1 rule. Similarly, medically necessary liquids or supplies do not need to follow this guideline. Both exception areas are subject to more intense scrutiny during screening, including opening the liquids or gels.