Human consumption and food security

CLEM provides functionality to feed the people present on the farm (Labour) from the food types available (Human food store) either by set amounts or using a targeted feeding with desired targets such as daily energy, fat, protein, or vitamin intake needed per person.

The initial design of human consumption uses a logical, process-based simulation approach. Human feeding is more difficult to represent than the ruminant feeding where there is much greater control over food supplied and the animals have little choice, but eat what is provided, when it is provided, and then the model moves through a detailed energy model to determine growth and survival. We do not use such a detailed approach for the human consumption.

The individual people to be fed are provided as the Labour resource.

Hired labour in the labour resource can be used to represent non-farm people who also need to eat the farm produce and the feeding activities have switches to include hired labour in the calculations.

A relationship is provided to determine the adult equivalent of each person based on their age. This is provided as a Relationship placed below the Labour component with a Name containing "AE" for identification. If omitted, all people are assumed to be 1 AE.

People can only consume from the Human food store. This is where all the crop products are placed at each harvest. Further activities can transfer, sell or work with this resource before being eaten.

Each Human food store type defines the edible proportion of the harvested raw product. It is the raw product that is tracked for carrying and transportation, but the edible proportion is used to track intake limits and nutritional content.

Each food type can be defined in any units (e.g. litres, each such as eggs, kg) and a conversion to kg is provided so that all food is worked with in kg.

The nutritional details of each food type are provided as conversion metrics with a Resource units converter component. You can add as many as are needed. These could include energy, fat, protein, or vitamins. These components also provide the daily amount of the nutrition that is obtained elsewhere, outside the simulation.

Each food type can specify the number of months before the food spoils and is unfit for human consumption. The food will be reported as spoiled after this date and is removed form the system and so is currently unavailable for other activities such as feeding pigs.

Two feeding activities are provided. The first (Feed people) is used to feed a specified amount to specified individuals. The second activity undertakes a process of trying to feed people up to specified targets from food available on farm and to be purchased if allowed.

Regardless of the activity, as people are fed each individual tracks the type and quantity of food eaten in the time-step for reporting. This means that summaries of type and quality of food can be reported at the end of the time-step (month). This also means that a combination of feeding activities can be used, and a targeted activity performed after a simple feed activity will recognise the food already eaten. A simple feeding activity performed after a targeted activity will not know about food intake and could therefore over feed the people.

Feeding activities will obey any timers used. This could allow seasonal changes in intake to be considered

This activity (Feed people) can be used to feed a specified amount of a given food or amount per AE to people. This could include feeding milk to infants, or a set amount of wheat to all people.

The Feed people to targets activity will attempt to feed the people present up to specified targets. It includes a switch to also consider the hired labour in the decisions.

A daily intake limit is defined in this activity that defines the limit (kg) that people can eat per day. This is required to give the model an upper limit of intake and stop feeding before targets are reached.

The activity can also indicate a mass of food eaten outside of the model process. This will contribute toward the daily intake limit and reduce the food stores that can be consumed.

See also