Human Nutrition, Diet, Food Safety, and Digestion
Human Nutrition
Understanding Nutrients
Nutrition is the set of processes by which the body receives, transforms, and incorporates the necessary nutrients for its cells. Nutrients are chemical compounds in foods that cells need to live.
Features of Nutrients:
- Energy Efficiency: Supplying energy for the functioning of cells.
- Plastic or Repair: Providing components for growth and renewal of cells that are destroyed.
- Regulatory: Supplying chemical substances that control the reactions of the cells.
Types of Nutrients
- Carbohydrates:
- Simple: An energy source that is digested and absorbed quickly.
- Complex: Require a longer digestion.
- Lipids: Have three energetic functions.
- Fat: Energy function and form deposits in reserve.
- Other: Plastic function.
- Vitamins: Have regulatory functions.
- Proteins: Have plastic functions and are the main components of the structure of the cells. They also have a regulatory function.
- Water: The most abundant component of the body. It serves to cool the body and helps eliminate waste.
- Minerals: Unfold the plastic function, constructing the structure of bones.
- Vitamins: Have a regulatory function, act in very small quantities, and must be taken together with food.
Food Classification and Balanced Diet
Food Groups
Dairy products, meat, fish, eggs, vegetables, tubers, nuts, fruits, bread, pasta, cereals, sugar, and fat.
Balanced Diet
A balanced diet allows the individual to maintain good health. It must include:
- Calories and the necessary nutrients.
- Calories should come from carbohydrates.
- Animal protein should be 40%.
- Absorb vegetable fats.
- Fiber, bluefish, and vegetables for bowel movement.
- Water and minerals.
- The diet has to be varied.
Food Errors: Can cause digestive disorders and affect the overall functioning of the body.
Food Safety and Preservation
Food Chain Stages
- Refrigeration: Food between 0 and 6ºC decreases the activity of germs.
- Freezing: At -18ºC, microbial and enzymatic actions stop.
- Sterilization: Heated to 110ºC to kill germs.
- Pasteurization: Between 60ºC and 80ºC, not all germs are destroyed.
- Use of Additives: Substances that prevent the proliferation of bacteria.
Food Hygiene
Food contamination comes from people, animals, and the environment. Foods exposed to contamination include fish, eggs, canned fruits, vegetables, beef, and milk.
Eating Disorders
- Arteriosclerosis: Thickening of the inner wall of the arteries, caused by excess cholesterol that forms atheromas.
- Obesity: An excessive amount of body fat, which is a risk factor for other diseases.
- Anorexia: The obsessive pursuit of thinness. Symptoms include rejection of food and excessive exercise.
- Bulimia: Eating more than necessary and, to prevent weight gain, vomiting after eating, drinking, or taking weight loss medication.
The Function of Digestion
Food is broken down by enzymes, and digestive juices break the molecules and turn them into smaller ones that enter the body and can be used by the cells.
Digestive System
- A 9-meter tube where food passes.
- Glands lead their juices to the tube.
Layers of the Digestive Tube
- Inner layer or mucosa: Secretes digestive juices and mucus that protect the surface.
- Muscle layer: It has fibers of involuntary and voluntary contraction.
- Nerves: Control the movement of food through the tube. Food is transported by waves of contraction and relaxation of muscles (peristaltic movements).