Physiological
Physiological factors affect the body’s need and desire for food. If the body is to remain healthy and function correctly it must have adequate amounts of food containing the essential nutrients.
Hunger
Hunger may be defined as that feeling of emptiness, weakness or pain caused by a lack of food. It becomes more intense as time passes, until we are able to think of little else but food. For those suffering extreme hunger, relieving the body of this pain is the focus of life.
Hunger is controlled by a small gland in the base of the brain called the hypothalamus. The hypothalamus has a number of functions in the body, and works closely with the pituitary gland to:
Hunger is controlled by a small gland in the base of the brain called the hypothalamus. The hypothalamus has a number of functions in the body, and works closely with the pituitary gland to:
- control body temperature
- regulate appetite, thirst and body fluids
- induce sleep and wakefulness
- control the release of growth and sex hormones from various glands throughout the body.
Appetite
Appetite is the desire for food even when the body is not hungry. Appetite can be triggered by the sight of appetising food, the aroma of food in preparation, and even the mention of food in conversation. The hypothalamus registers these cues from the senses and sends messages to the brain which encourage you to think about food. The salivary glands are stimulated and produce extra fluid: your mouth then begins to water. Unlike hunger, if appetite is not satisfied it will eventually go away.
Nutritional requirements
Many of us select food that is nutritious because we know that we will feel and stay healthy. The food we eat should provide essential nutrients that the body can absorb, and metabolise. There are five different categories for nutritional requirements they are body size/type, age, level of activity, gender and health status.
Body size/type are the nutritional requirements of different sized human bodies vary. Individuals who have larger builds require more nutrients to maintain and operate their body processes. Similarly, those with a smaller body size require less protein for the maintenance and repair of body tissues because their body mass is less.
Age
The human body undergoes specific growth stages throughout life. An infant’s body has an enlarged head, and the arms and legs are short in relation to the rest of the body. Early childhood sees dramatic changes in body proportions. The arms increase in length and muscle tone, which allows for greater movement and coordination, and the legs extend to make up half the body’s height. The period of growth and development continues throughout adolescence until the body attains a more adult form.Because nutrients carry out specific functions within the body, the amount of nutrients needed by an individual is regulated by the growth processes.
Level of activity is determined by an individual who is physically active needs to consume more energygiving foods than an individual who leads a sedentary (less active) life. A sedentary person requires less of all nutrients than an active person. If an individual consumes large quantities of energy but does not move around much, the body stores the excess as adipose tissue (fat).
Gender
The sex of an individual also determines their nutrient requirements. Biological activities such as menstruation and childbirth mean that women need to have a higher dietary intake of iron and calcium. Men have a higher pro portion of muscle tissue on their bodies, so they require a higher intake of protein than women.Gender will also affect the parts of the body where adipose tissue is stored. Women are most likely to find extra adipose tissue on their upper arms, bust, waist, hips and thighs.
Health status
A person’s state of health may lead them to consume certain types of food and/or less of other types of food. If, for example, a person has high cholesterol (that could eventually lead to heart disease), they may opt to reduce the amount of animal fat in their diet. Some diseases that may be related to poor diet include beriberi, pellagra, rickets, scurvy, osteoporosis and anaemia. Anaemia is a deficiency disease where the person affected is deficient in red blood cells and/or haemoglobin.
Body size/type are the nutritional requirements of different sized human bodies vary. Individuals who have larger builds require more nutrients to maintain and operate their body processes. Similarly, those with a smaller body size require less protein for the maintenance and repair of body tissues because their body mass is less.
Age
The human body undergoes specific growth stages throughout life. An infant’s body has an enlarged head, and the arms and legs are short in relation to the rest of the body. Early childhood sees dramatic changes in body proportions. The arms increase in length and muscle tone, which allows for greater movement and coordination, and the legs extend to make up half the body’s height. The period of growth and development continues throughout adolescence until the body attains a more adult form.Because nutrients carry out specific functions within the body, the amount of nutrients needed by an individual is regulated by the growth processes.
Level of activity is determined by an individual who is physically active needs to consume more energygiving foods than an individual who leads a sedentary (less active) life. A sedentary person requires less of all nutrients than an active person. If an individual consumes large quantities of energy but does not move around much, the body stores the excess as adipose tissue (fat).
Gender
The sex of an individual also determines their nutrient requirements. Biological activities such as menstruation and childbirth mean that women need to have a higher dietary intake of iron and calcium. Men have a higher pro portion of muscle tissue on their bodies, so they require a higher intake of protein than women.Gender will also affect the parts of the body where adipose tissue is stored. Women are most likely to find extra adipose tissue on their upper arms, bust, waist, hips and thighs.
Health status
A person’s state of health may lead them to consume certain types of food and/or less of other types of food. If, for example, a person has high cholesterol (that could eventually lead to heart disease), they may opt to reduce the amount of animal fat in their diet. Some diseases that may be related to poor diet include beriberi, pellagra, rickets, scurvy, osteoporosis and anaemia. Anaemia is a deficiency disease where the person affected is deficient in red blood cells and/or haemoglobin.
Reactions to food
Our personal perceptions have a major influence on our food selection. Individuals select or reject food based on their reaction to the food’s physical appearance, its presentation, smell, and texture. We use our senses to gauge the quality and appeal of food, and judgements based on these reactions are called sensory perceptions. Attractive colours and the creative arrangement of food stimulates the appetite and the salivary glands, creating the desire for specific foods that may not other wise have been chosen. Food preparers also take care in the placement of food on the plate because they are aware that the aesthetic appearance of the meal can enhance or retard the appetite of those to whom it is served.Some people’s food choices are limited because they have a physical reaction to specific foods or ingredients. The reactions vary between individuals but may include abdominal swelling, vomiting, diarrhea, itches and skin rashes, wheezing, headaches and disturbed sleep.