Human Nutrition: Essential Nutrients and Balanced Diet
Food and Nutrition
Nutrition describes the set of processes by which an organism obtains energy and matter necessary to develop its own structures and perform vital functions. Nutrition is an involuntary process that involves various organs and systems. Food makes up our diet and is necessary for our nutrition. Food is a conscious and voluntary act.
Types of Nutrients
- Inorganic nutrients: These can come from animal and plant sources, and also from non-organic sources. Examples include water and mineral salts.
- Organic nutrients: These are found only in organic food sources. Examples include carbohydrates, lipids, and proteins.
Vitamins
Vitamins are nutrients that may be lipids or proteins. Our body cannot synthesize them and must ingest them with food. They are essential for growth and proper functioning of the organism. They are very abundant in fresh food of plant origin, including fruits and vegetables. A lack of vitamins causes the onset of deficiencies.
Food Energy Value
The energy value is represented in calories or kilocalories. A calorie is the amount of heat that must be supplied to one gram of liquid water to increase its temperature by one degree Celsius.
Energy Needs in Humans
Basal metabolic rate is the amount of energy that our body consumes in a day, in complete rest and at a constant temperature. This rate varies from individual to another and depends on various factors: health status, weight, age, or sex of the person.
Different Types of Food
According to their role in the organism, foods can be classified into three types:
- Energy foods: Serve as a source of energy so the body can perform its vital functions. These foods are rich in fats and carbohydrates. Examples: bread, cereals, sugar.
- Structural or plastic foods: Are necessary to form cells, tissues, and organs of our body. They are essential for nutrition. Examples: yogurt, cheese, meat.
- Regulatory or protective foods: Are essential because they allow our body to properly use other foods and perform other functions adequately. Examples: fruits and vegetables.
Healthy and Balanced Diet
Diet is the set of solid and liquid substances we consume as food throughout the day. Diets can be specific for each person, depending on age, sex, and physical activity. A diet is complete, varied, and balanced when it provides all kinds of foods and sufficient quantities of nutrients and energy for the body to cover its daily energy expenditure.
Disorders Related to Food
Illness is caused by imbalances in the diet. The most common diseases related to food are:
- Malnutrition: Caused by a lack of nutrients, mainly due to an inadequate diet or lack of food.
- Obesity: Excess body fat, which usually involves a large weight and reduces the lifespan of people who suffer from it.
- Anorexia: Characterized by an intense fear of weight gain and a distorted perception of one’s own body, which causes the person suffering to look fat even when it is not at all.
- Bulimia: Characterized by excessive concern about weight and body figure. The person eats in excess, even without appetite, hiding, and eliminates the excess calories by vomiting or abusing drugs.
Food Preservation and Handling
Conservation techniques:
- Cold storage: Foods are kept at low temperatures. It can be carried out by means of refrigeration or freezing.
- Heat preservation: High temperatures are applied for a short period of time, with the goal of eliminating microorganisms without altering the food. Pasteurization and sterilization.
- Dehydration: Based on the elimination of water from food, which prevents microorganisms from developing.
- Addition of substances: Various substances are incorporated into the food to prevent the growth of microorganisms.