Human nutrition as an automatic system of control

摘要

The basic human needs are food and water - without them there is no human life. Sam Maslow has grouped them in the first group of physiological needs - those that have to be satisfied before other groups' needs in the hierarchy of human needs are satisfied. The man can feed himself- taking and accumulating energy (calories) or not feed himself - not taking and accumulating energy (calories) and water. The nutrition control system is a biological automatic control system, which consists of the following control blocks: gastric system - the object -block that is to be regulated, human brain as the regulator and enteroinsulary hormones and neurotransmitters as the measuring transmitter(s) in the feedback loop. The reference-value is the human desire for food intake created in the human brain, while the state of the object of control is the information relating to the quantity of the food taken. The decision to take food is made by the human brain and can be represented with one of the two states (positions) of the two-position relay (take or do not take food). The problems can occur due to the inadequacy, slowness of the feedback - since the human being feels whether he has taken too little, too much or the right amount of food usually (only) 25-30 minutes after food intake. Thus, a question rises: "How to know when to stop food intake?" It is interesting to note that different proverbs exist about food intake, and these can be interpreted in the light of automatic control systems.