Be sure to bring high-calorie snacks and a lunch to meet the demands of your hike. 2. Take breaks to eat in the shade, hiking in the heat can make you lose your appetite. 3. Electrolytes help to keep you balanced which we have found helps us with our appetite. When your electrolytes become imbalanced and you're low on salt it brings on all kinds of symptoms including headaches and loss of appetite. So it's best to keep ahead of the problem!