Glossary Detail

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name of the term: Fat

Short introduction

  • Fat, together with carbohydrates and protein belong to the group of macronutrients.
  • Dietary fat consists for approximately 98% of triglycerides.
  • A triglyceride is composed of 1 glycerol molecule connected with 3 fatty acid molecules.
  • Animal fat that mostly contains saturated fatty acids is solid (hard) at room temperature.
  • Vegetable fat (oils) contains mostly unsaturated fatty acids and is liquid at room temperature.

Main natural sources

  • Dietary fat is derived from both animal and plant products.
  • Animal fat: butter, milk and other dairy products, eggs, meat, poultry, fatty fish as salmon, herring and mackerel but also ‘hidden’ in cookies, fast foods and snacks.
  • Plant fat: vegetable oils like sunflower oil, corn oil, olive oil, as well as (pea)nuts, seeds, avocados and olives.

Main function

  • Major source of energy for the body: 1 g of fat provides 9 kcal (38 kJ).
  • Fat-soluble vitamins (vitamin A, D, E, K) need fat in order to be absorbed and stored.
  • Provides the essential fatty acids α-linolenic acid (ALA) and linoleic acid (LA), which are not made by the body and must be obtained from food.
  • Storage. Excess energy is stored in the body (in fat cells known as adipocytes) as fat for future use. When the body stores more fat then it uses, fat cells will expand causing weight gain. In case of e.g. heavy dieting, fat cells will shrink causing weight loss.
  • Forms a protective cushion around vital organs. This protects against outside impacts or sudden movements.
  • The thin fat layer directly underneath the skin acts like insulation and helps keep heat inside the body and protects the inner body from any extreme changes in temperature.
  • Improves taste and texture of food.

Deficiency disease

  • Marasmus is caused by a severe deficiency of nearly all nutrients (inadequate total energy intake), especially protein, carbohydrates, and fat. It is commonly represented by a shrunken, wasted appearance, loss of muscle mass and fat mass beneath the skin. Symptoms e.g.: unusual body temperature, anaemia, oedema, dehydration (thirst, shrunken eyes), visual manifestations (due to vitamin A deficiency), skin manifestations and ear, nose, and throat symptoms.
  • Possible deficiency of fat-soluble vitamins A, D, E, K – see also: fat-soluble vitamins.
  • Possible deficiency of essential fatty acids. Signs and symptoms e.g.: allergic or atopic tendencies (eczema, asthma, hay fever), visual symptoms (poor night vision, visual disturbances), attention problems (poor concentration, attention and memory problems), emotional sensitivity (depression, excessive mood swings, anxiety), disturbed sleep-wake cycle and decreased immunity (increased susceptibility to diseases and infection, poor wound healing).
  • In infants and children growth may be decreased and in children it may negatively influence cognitive (brain memory and performance) and behavioural performance.

Recommended daily intake

Latest Dietary Reference Intakes (DRIs)
Institute of Medicine (IOM)

Age categoryPer day
Infants 6 – 12 month30 g (AI)
1 – 3 years
4 – 8 years

AI = Adequate Intake.
ND = Not Determined.

Synonyms: Fat

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