FATS

FATS

INTRODUCTION: Fats are an essential part of our body, accounting for a sixth of our body weight. The cells and tissues of our body have fat as an integral part. The vital organs (brain, heart, liver) are protected by a sheath and water, which holds them in place and prevents injury. The nerves are also protected by fat. A layer of fat beneath the skin acts as a insulation against cold. The fat around the joints acts as a lubricant and allows us to move these smoothly. Thus fat is a crucial part of the body composition.

Fats are the best known members of a chemical group called, the lipids. They constitute an important part of our Indian dietary and supply 10-30 percent of the total energy needs. Food fats include solid fats, liquid oils and related compounds such as fat-soluble vitamins and cholesterol.

In the middle of last century, fats were expensive and a meal containing large amounts of fat was called a ‘rich meal’.  Persons consuming such meals were thought to be healthy. But with the improvement in the methods of production and their availability, there has been an indiscriminate increase in fat intake in some sections of society leading to overweight and obesity. The weight increase discourages movement, increases pressure  on the circulation, respiration and skeletal frame. Hence it is recognized as a risk factor for several chronic ailments.

Fats are not only as essential body component, nutrient and compact storage fuel,  but also as a health hazard. We need to achieve a realistic balance between meeting our needs and avoid health problems due to excessive intake. 

COMPOSITION: Lipids is an overall group, which includes all fats and related compounds. The word is derived from the Greek word lipos which means fat. It is used in combination words to name fat-related health problems, e.g., hyperlipidemia refers to elevated level of blood fats.

Like carbohydrates, lipids contain the elements carbon, hydrogen and oxygen, and some contain phosphorus and nitrogen. Lipids have fewer oxygen atoms in their structure than carbohydrates.

Therefore more oxygen is needed to oxidize lipids and more energy (about 2.25 times) is released per g of lipid as compared to a g of carbohydrate.

Lipids are an essential part of the body structure. Body fat accounts for 15 to 20 percent of body weight in healthy non-obese men and 18 to 25 per cent in healthy non-obese women. The fat content of body increases in secondary individuals and senior citizens if they do not have active leisure time activities.

Lipids are widely distributed in nature. They are soluble in organic solvents, namely, ether, chloroform, benzene and other fat solvents. Fatty acids, fats and oils, phospholipids, sterols and lipoproteins are some of the groups of lipid compounds, which are important in the study of nutrition.

SOURCES

Vegetable oils, used in food preparation, are extracts of oilseeds and nuts. The important sources of vegetable oils are depicted. Butter and ghee are animal fats extracted from milk.

Plant oils are hydrogenated to form an almost solid fat known as vanaspati. Vanaspati is usually fortified with vitamin A and D, as it is used in place of ghee. The sources of fats in our dietary are listed in table. Oils, butter, ghee and vanaspati contribute the visible fats in the Indian dietary. The amount of oils and fats in the diet vary with the region. As these are expensive foods, the amount and kind used in the dietary, varies with the socio-economic status of the family. The animal foods, milk, egg, meat and liver, which contain fat, are sources of hidden fat in the diet. Nuts, oil seeds, milk, eggs and meat supply not only fat but also protein, minerals and vitamins of the B-complex group Ghee, butter, eggs and liver are good sources of vitamin A. Some refined oils and vanaspati are fortified with vitamin A. Use of ghee, butter, fortified refined oil or vanaspati helps to meet a part of the day’s need for vitamin A.

Table: Sources of fats

Food	g / 100g	Calories/ 100 g
Visible Fats
Oil, vegetables	100.0	900
Vanaspati	100.0	900
Ghee, cow’s	99.5	895
Butter	81.0	729
Invisible Fats
Oilseeds & nuts	37.5-64.5	537-681
Mutton, muscle	13.3	194
Eggs, hen	13.3	173
Liver, sheep	7.5	150
Milk, cow’s	4.1	67

Vegetable oils contain poly-unsaturated fatty acids such as linoleic, linolenic and arachidonic-acid. Linolenic and arachidonic-acid are required for growth and maintenance of integrity of the skin. It may be noted that vegetable oils are a fairly good source of essential fatty acids.

It is easier to control visible fats in the diet than that which is hidden. For example, one can monitor use of butter, ghee and oil used directly. Invisible fats include the cream in the milk and dahi, nuts used in preparation and as such, egg yolk, oil used in seasoning vegetables, dal and salads. Even toned milk contains 3 per cent fat. Invisible fat contributes about 10 or more per cent of total energy in the diet.