Your bag should be no more than 25% of your body weight and therefore you need to select your kit wisely. You also want to find kit that fits well, making life more comfortable but ultimately safer.
The big advice we give every year for food is 'Go BIG on pudding!' but to do this you need to plan and trial your food choices, pack plenty but make sensible choices, not just sweets and remember Pot Noodles. are classed as a snack, they are not a meal!
A few ideas from home, take it or leave it but if you are not sure how to make the most of your food packing and choices have a watch.
This is not for the faint hearted! If you want a super high calorie version of traditional flapjack then have a look at this. Make it at your peril!