The danger with this is the body requires a certain amount of calories to perform in peak condition. Limiting your body from these precious calories weakens the body. The hiker tends to stumble more and is prone to making judgment errors. Not something you want to do on an edge of a cliff with 5000 feet of air between you and the bottom. Protect your food.
Thieves are abundant.
I am not talking about your fellow hikers but the clever creatures that roam the canyon floor. Scorpions and rattlesnakes are docile compared to the ravenous squirrels and ravens. Do not let their meekness fool you. They are the nightmare of every hiker. At Monument Creek Campground we met a lone hiker, who was clutching a small daypack.