Map your opportunities to eat
Note when you leave, when you expect to arrive and where you can realistically get a meal. A connection that looks long on paper may be occupied by walking or queues. Have a backup for a delay without packing as though every trip is an expedition.
If your journey crosses a normal mealtime, think about a meal as well as a snack. A bar can be useful between stops without carrying the whole plan.
Choose food that is easy to access
Put a snack in a part of your bag you can reach while seated. Keep anything that needs cooling appropriately stored and follow the pack instructions. A food that is convenient at home may be awkward without a table or utensils.
Individually wrapped items can be easy to organise, but keep the packaging until you can dispose of it properly. It also carries ingredient information if you need to check it.
Check the rules for your destination
Do not assume that a food allowed on one journey can be taken across every border. Transport and destination rules vary. Check the relevant official guidance before carrying food internationally, particularly products with animal ingredients.
This article is a packing framework, not a statement that a particular bar is permitted in every country. Henry contains egg, so the ingredient list is relevant when checking any applicable rules.
Bring variety you actually want
Choose familiar foods rather than making travel day the first test of an unfamiliar snack. Mix convenient options according to your preferences, and include a plan for drinks rather than expecting food to solve that need.
After the trip, note what you used and what you carried unnecessarily. That is often the best guide to packing the next journey: a little preparation, accessible food and fewer last-minute decisions.