Topic 1 Introduction

Our body in order to survive, grow and meet the usual expenses for its maintenance and activities, needs to be continuously replenished with the nutrients contained in food.

Foods are transformed through digestion into more simple substances, called nutritional principles or nutrients:








  • Energetic
  • Plastic
  • Protective
  • Regulator
  • Stock

Energy per gram:

  • Carbohydrates: 4 kcal (17kJ)
  • Proteins: 4 kcal (17kJ)
  • Lipids: 9 kcal (37 kJ)