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Biology 2nd Baccalaureate

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2.4. Diets


The diet is a set of foods that are provided to an organism in a day. Depending on age, sex, physical activity, more or less amount of energy and nutrients will be needed.

Therefore, a balanced diet has to take into account the quantity of nutrients, the variety, the quality, the balance of its components and the suitability for each individual.

The diet should cover the daily needs of all the nutrients in the body.

Healthy diet

healthy diet is a complete and balanced diet.

  • Complete: provides food from all the groups of nutrients necessary for the body.
  • Balanced: contains the nutrients in the right proportions. According to the WHO (World Health Organization), a balanced diet is one that provides energy from 55-60% of carbohydrates30-35% of lipids and 10-15% of proteins.

En una dieta equilibrada la energía debe provenir de los glúcidos (55-60%), lípidos (30-35%) y proteínas (10-15%)

healthy diet is based on these criteria:                       

  • You have to include a variety of foods, from all groups and in the proportions recommended in the food pyramid.
  • Drink between one and two liters of water a day to be well hydrated and properly eliminate waste and toxins, but avoiding sugary drinks and soft drinks.
  • Consume salt moderately to prevent high blood pressure.
  • Eat foods rich in fiber and little refined to avoid excess calories consumed and promote intestinal transit.
  • Consume fresh fruits and vegetables daily to obtain vitamins, mineral salts and fiber.
  • Consume vegetable oils, mainly olive, and fish, due to their content in unsaturated fats, which are healthier than saturated ones.
  • Avoid the consumption of sausages and hamburgers due to their high content of saturated fat, increasing that of white meats such as chicken and reducing the consumption of sweets and pastries due to their high content of carbohydrates and fats.
  • Eat food, at least five times a day, but not very abundantly and never skip breakfast.
  • Breakfast has to be complete, with milk, cereals and fruit, to take the necessary energy at the beginning of the daily activity.
  • Dinners have to be light, to be able to recover energy but without impairing rest.
  • We have to do moderate physical exercise at least three times a week and a daily rest of 8 hours.

Video:  A vegetarian diet can be balanced.

Mediterranean diet

The Mediterranean diet is the traditional diet of the countries bathed by the Mediterranean Sea (especially Spain, Portugal, France, Italy, Greece and Malta), and it is characterized by very healthy and balanced eating habits.

The main characteristics of this diet are:

  • High consumption of plant products (fruits, vegetables, legumes, nuts), bread and other cereals (wheat being the base food).
  • Olive oil as the main source of lipids.
  • Preferential consumption of fish.
  • Low consumption in sugars.

Hypocaloric diet

The calorie diets contain less energy foods (carbohydrates and fats) than recommended for a balanced diet, so they are recommended for people looking for how to lose weight if it is excessive.

Persona con sobrepeso mide su cintura.

Hypercaloric diet

The calorie diets contain more energy foods recommended for a balanced diet, so are suitable for people with extreme thinness that need to increase their weight.

Low cholesterol diet

The diets low in cholesterol are recommended for people with hypercholesterolemia. The aim is to reduce the ingestion of eggs, shellfish, meats and fats of animal origin and to increase the consumption of oily fish and vegetable oils, preferably olive, which contain unsaturated fats.

High residue diet

The diets high in waste, are characterized to include enough fiber - rich foods. They are recommended for people who have constipation problems.

Bland diet

The diets soft contain low fiber foods, recommended for people with intestinal obstruction or slow gut, such as after some surgical operations.

Answer in your notebook

2.7.- For a few days you have been writing down the foods that make up your diet. Analyze your diet according to the nutrients (% in lipids, carbohydrates, and proteins) and assess whether or not it is balanced, indicating what changes you should make in your diet to improve your diet.

You can help yourself with this nutritional calculator, or some of these others.

How many calories do you eat on any given day?


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Biology and Geology teaching materials for Compulsory Secondary Education (ESO) and Baccalaureate students.