When hiking, it is important to follow a few basic nutritional principles: 

Stay hydrated

Keeping hydrated is extremely important on hikes, even in winter, when the air can be dry. The standard bottle size is 1 litre, but this is often insufficient. Camelbags are a good alternative to bottles: they save space, hold up to 3 litres and allow you to drink through tubes while walking.

You may choose any drink you like, but it shouldn’t contain alcohol or sugar. During winter, it is a good idea to carry around a thermos flask. By doing this, your body won’t have to use up extra energy warming up a cold drink.

Ideal Snacks

You need to recharge your batteries while on tour with food. It is possible to save a lot of weight in your rucksack if you pack the right snacks.

My experience is that people usually bring too much food. It’s all about variety: something salty (sausage or cheese), something sweet (chocolate), something energy-rich (bars, dried bananas), and something juicy (apple or other fruit). The bread can be omitted.