Energy is required to make food. Whether we feed cows to produce milk or apples from the trees, energy is required in different forms from the beginning to end. The apple might be an emblem of simplicity, but accounting for all the energy needed to produce one is another matter. You have to factor in pesticide production, fertilizer manufacturing, irrigation, harvesting, sorting, and transportation. Electricity and diesel fuel are needed to drive all these steps, and coal mining and oil extraction come with their own energy costs. And that’s just the apple. Here is a list of some items of foods in Sweden.
Even specially bred hens for this purpose convert food to eggs with only 15-20% efficiency
Mega joules required per 1 Kg=18
Shelled shrimp, wild
High energy cost comes from fuel required to run a shrimp boat.
Mega joules required per 1 Kg=220
Fuel required in importing adds to the energy cost. But lower perishing rate means that they can be transported by cheaper means like ship.
Mega joules required per 1 Kg=8.6
Requirement of food for dairy cows is far less than cows reared for meat. Milk energy requirement makes it most efficient.
Mega joules required per 1 Kg=5