Amongst the 3 nutrients (fats, carbohydrates and proteins) fat has the highest energy content of 9.3 kcal/g.
Fat and cholesterol consumed in food is emulsified by the bile acid and is reabsorbed through the intestinal walls. Furthermore, all somatic cells (cells in the body) are capable of synthesising fat. However our bodies can not form certain polyunsaturated fatty acids. These fats (e.g. linoleic acid) are absolutely vital for the body and must be consumed in the form of food.
The body creates new fatty tissue if the absorbed nutrients provide more energy than is being used. 1 kg body fat is ca. 7000 storied kcal. The fat storage tissue in the body is constantly being decomposed and recomposed. It can therefore not be equated to a stable, inactive reserve which is only utilised when needed.
Fat should make up no more than 30% of the nutritional calories however German nutrition contains an average of 40% fat calories.
Fat is made out of fatty acids that is to say hydrogen and oxygen atoms which are linked to carbon atoms. The classification of fatty acids is dependant on the degree of saturation or the number of the bonded hydrogen atoms. Saturated fats contain the most hydrogen, polyunsaturated fats contain the least.
One differentiates fatty acids according to their degree of saturation:
- saturated fatty acids
- monounsaturated fatty acids
- polyunsaturated fatty acids
The Role of Fat in the Human Body:
- Fats are used as energy transporters. Unnecessary fat is stored in the body as an energy reserve.
- Fat contains certain polyunsaturated fatty acids, which the body needs and cannot synthesise by itself.
- Fats contain fat-soluble vitamins and pro-vitamins. The absorption of these vitamins is only possible with fat.
- Fat pads protect organs from injuries and act as a type of thermal insulation.
- Fat is a flavour carrier for fat-soluble aroma and flavour additives.
Fats That Heal, Fats That Kill: The Complete Guide to Fats, Oils, Cholesterol and Human Health
Eat Fat, Lose Fat: The Healthy Alternative to Trans Fats, Mary Enig, Sally Fallon