Question

What are fats? What are its function?

Answer 1

Answer:

fats are essential to give your body energy and to support cell growth. They also help protect your organs and help keep your body warm. Fats help your body absorb some nutrients and produce important hormones, too. Your body definitely needs fat.

Explanation:

function

Provision of energy

Fats are a source of energy in the human diet, together with carbohydrates and proteins, the other two main macronutrients. Fat is the most concentrated source providing 9 kcal per 1 gram consumed, which is more than double the energy content of protein or carbohydrate (4 kcal per gram) and more than quadruple the energy content of fibre (2 kcal per gram). Fat can be stored in the body’s fat tissue, which releases fatty acids when energy is required (see box: Body fat).

Structural component

The membranes around the cells in our body physically separate the inside from the outside of the cell, and control the movement of substances in and out of the cells. They are mainly made of phospholipids, triglycerides and cholesterol (see Facts on Fats: The Basics). Both length and saturation of the fatty acids from phospholipids and triglycerides affect the arrangement of the membrane and thereby its fluidity. Shorter chain fatty acids and unsaturated fatty acids are less stiff and less viscous, making the membranes more flexible. This influences a range of important biological functions such as the process of endocytosis in which a cell wraps itself around a particle to allow its uptake.1

The brain is very rich in fat (60%) and has a unique fatty acid composition; docosahexaenoic acid (DHA) is the major brain fatty acid. The lipids of the retina also contain very high concentrations of DHA.2

Carrier of vitamins

In the diet, fat is a carrier for the fat-soluble vitamins A, D, E and K, and supports their absorption in the intestine. Consuming sufficient amounts of fatty foods that contain these vitamins is thus essential for adequate intake of these micronutrients.

Other biological functions

Our bodies cannot produce the polyunsaturated fatty acids (PUFA) linoleic acid (LA) and alpha linolenic acid (ALA) as described in Facts on Fats – the Basics. Without these essential fatty acids some vital functions would be compromised, thus they must be provided by the diet. LA and ALA can be converted to longer chain fatty acids and compounds with hormone-like or inflammatory properties (such as prostaglandins or leukotrienes, respectively). As such, essential fatty acids are involved in many physiological processes such as blood clotting, wound healing and inflammation. Although the body is able to convert LA and ALA into the long chain versions arachidonic acid (AA), eicosapentaenoic acid (EPA), and, to a lesser extent, to docosahexaenoic acid (DHA), this conversion seems limited.3 The longer chain fatty acids EPA and DHA are said to be “conditionally essential” and it is recommended to consume direct sources of these particular long chain fatty acids. The richest source of EPA and DHA is oily fish, including anchovy, salmon, tuna and mackerel. See Facts on Fats – the Basics for a more complete overview of the most common fatty acids and foods in which they can be found.

Cholesterol

All animal cells contain cholesterol, a lipid that plays a role in the membrane’s fluidity and permeability. Cholesterol is also a precursor of vitamin D, adrenal and sex steroid hormones, and bile salts that emulsify and enhance absorption of fats in the intestine.4 The main dietary sources of cholesterol are cheese, eggs, beef, pork, poultry and (shell) fish.

Answer 2

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➠ Fats are composed of carbon, hydrogen and oxygen. The oxygen content in these nutrients is much less. They produce more energy than carbohydrates do-one mole of fat releases 9.45 Kcal of energy. Common foods rich in fats are butter, cream, vegetable oils, fats of meat and fish liver oils. Fats and oils are made up of fatty acids and glycerol.

Functions of fats are :-

1. It produces energy in the body like carbohydrates.
2. It is an important storage form of food.
3. It serves as a solvent for fat-soluble vitamins.
4. Fat under the skin protects the body against a rapid loss of heat (insulation).