Reproduce the carrying conditions
Use the same belt, vest or shorts pocket that you expect to wear. Put the planned items in their real packaging rather than carrying an empty wrapper as a size test. Weight, shape and movement change once the pocket is loaded. Include the other objects that share the compartment so you can notice whether keys press into food or a phone blocks access.
Choose a short local outing for the first trial. You are checking a carrying method, so there is no need to create a demanding session merely to justify the test. Notice whether the packet slides, rattles or works its way towards the opening. Stop to make changes rather than repeatedly reaching behind you while negotiating traffic or an uneven path.
Try the opening and the aftermath
At a safe place, check whether you can open the packaging with the hands and clothing you will actually have. Gloves, damp fingers and a tightly stretched pocket can change a seemingly simple task. If you prepare packaging in advance, consider whether that exposes the contents to moisture or makes them leak. A convenient opening is not useful if it empties into the bag.
Have somewhere for the wrapper after use. A small, accessible waste pocket or reusable pouch keeps sticky packaging away from clean layers. Check that you can close it and that it will not release rubbish when you remove another item. The carrying system includes the return journey of the packaging, not only the moment you take the food out.
Keep the experiment limited
Change one part of the arrangement at a time. Moving a packet from a rear pocket to the front is a different test from changing the food, clothing and carrying system together. Write down the specific result: the wrapper rubbed against the phone, the pocket was hard to reach, or the contents became crushed. These notes point to a practical adjustment.
This is not a recommendation for a particular amount or type of food. Use your own established needs and seek qualified advice for individual nutrition questions. For the carrying problem, success is simpler: the item remains secure, you can reach and identify it, and the empty packaging has a place. Confirm the same arrangement with the complete race or outing kit before relying on it far from home.
