Here's my rations for 3 days & 2 nights in winter. It's inexpensive, compact, and fun to plan:
Lots of calories in sugars, fats, proteins and carbs.
I mix my own food in ‘soup & sauce’ bags, so I can put boiling water directly into the bags, seal them up, and leave them for 10 minutes to rehydrate. I pop the bags into a jiffy-bag for insulation, so the food stays hot.
The porridge-mix has both sugar and powdered milk, so all I have to do is stir it properly to get it evenly mixed.
Those sachets of tuna and the long-life tortillas make a decent lunch; I might supplement with a home-made peanut-butter and cereal-bar.
The chorizo’s important, especially when it’s cold (Pork scratchings are good too!). The fat from it is a useful way for my body to generate heat in the evenings. A few chunks of that in my dehydrated spicy chili mix (with couscous) is quite tasty.
The hot beverages are important. I nick a few sachets from coffee-shops and service-stations from time-to time - they’re handy. Coffee in the morning, tea during the day and evenings. When it's could, I use more sugar. A bit OCD, but that’s how I am with these things.