Everybody's nutritional needs will be different. Variations in weight, size, walking style, and metabolism will vary your calorific needs. 3000 calories a day worked fine for us over 14 days. Any longer time or distance would require a substantial increase in calorie intake

 Dehydrating food is not difficult. You can purchase a commercial food dehydrator at a reasonable cost, you can build a dehydration box for less, and for small amounts of food it is quite possible to use the oven in your own kitchen. 

Constructing a meal for midday or evening. A meal should have real flavour and texture. As a general rule a well constructed dehydrated meal should have between 160 and 170 calories per ounce (28g)(dry weight). The weight of a days food should therefore be around 18 oz (500g). Pasta, rice and potatoes in my view make an excellent base for a good meal where as cous cous and polenta do not. Once you have your base add some protein - meat or fish, a sauce for extra flavour, and a crunchy topping for extra texture.
Our Breakfast consisted of custom designed cereals and dehydrated milk. Designed cereal was mix of bran, granola, nuts, and raisins. Nuts have a very high calorific value. Typically over 72 calories per ounce for pecans, walnuts, and almonds.

Some example meals. More to follow

Fish Pie
At home
Dehydrate a piece of white fish (Cod) and bag up. Bag up mash. Bag up cheese sauce.
To prepare
Boil up 500ml water containing dehydrated cod. Boil for 5 minutes then pour off 70% of water and use to make up mashed potato. Place white fish onto mash. Use remaining 30% to make cheese sauce. Cover mash and cod in cheese sauce. Sprinkle with crushed corn or potato chips. Eat

 Philly Cheese Steak dinner.
At home Dehydrate tinned stewing steak and bag up. Bag up mash. Bag up parmesan cheese and dried onions.
To prepare Boil up 500 ml water containing dehydrated steak. Boil for 5 minutes then pour off and make up mashed potato. Place steak onto mash and cover mash and steak in parmesan cheese and onions.