[oskar]

To get to the camping spot you can piss or poop only the night before you leave.
Get on a diper the evening before and get the locking pants over them. You can change only at your camping destination when the tent is set up properly. Keep the diaper, since you have limited supplies you have to reuse that diaper to sleep in at night.
For lunch you should prepare baked beans, for each spoon that goes to your mouth one should go to the back or the front of your diaper, so be careful about the temperature of the beans.