When addressing food and water intake, too much of any one of these will be harmful. Balance them as much as you possibly can on your hiking and camping trip, especially if it will last for days and days. Sometimes what you want is not necessarily what you may need right there in the moment. Still, these urges will come about, so you have to constantly keep track of what you have ingested. Of course, it all depends on the weather and what you are doing that will determine what your body needs the most.
For example, you may start feeling an urge to eat when you are out on, say, a long hike if the weather is cool, when actually you may be dehydrated and need water. On the other hand, if it is hot and humid, you may feel the opposite – an urge to drink more water than you really need right then and there. Of course water is the most vital resource, so you need plenty of it. But, before you proceed to down another full bottle of it, ask yourself this question – when was the last time you ate something?
This is why many outdoorsmen document the exact times they eat, because it can be easy to forget to get some food in you, especially in the heat. Still, it can again be the other way around, and you really do need to drink water. If you end up eating a large meal while you are actually dehydrated, the food in your stomach will soak up the water that was in your body and leave you even more dried out. On top of that, food will make you sleepy at times, and when not balanced with enough fluids your rest will not be as regenerative as it could have been. Get to know your body, and develop the routine that is right for you during your outdoor expedition.