Fat and Fiber

Fat
Calories/gram: 9
Fats play a vital role in the human body and perform many functions. They are necessary for the absorption and utilization of certain vitamins like A, E, D and K. Fat deposit help to maintain body temperature against outside environmental influences and protects body organs such as the heart and the liver. Fats contain Essential Fatty Acids (EFA) which are essential for maintaining tissues in normal health.
Fats are composed of fatty acids (long carbon/hydrogen chains) bonded to a glycerol; they are typically found as triglycerides (three fatty acids attached to one glycerol backbone). Certain fatty acids are essential. Fats may be classified as saturated or unsaturated. Saturated fats have all of their carbon atoms bonded to hydrogen atoms, whereas unsaturated fats have some of their carbon atoms double-bonded in place of a hydrogen atom. In humans, multiple studies have shown that unsaturated fats are to be preferred for health reasons, particularly mono-unsaturated fats. Saturated fats, typically from animal sources, are next, while 'trans' fats are to be avoided; they have been banned in several locations (eg, New York City). Saturated and trans fats are typically solid at room temperature (such as butter or lard), while unsaturated fats are typically liquids (such as olive oil or flaxseed oil). Unsaturated fats may be further classified as monounsaturated (one double-bond) or polyunsaturated (many double-bonds). Trans fats are saturated fats but are typically created from unsaturated fat by adding the extra hydrogen atoms in an industrial process called hydrogenation; they are also called hydrogenated fat. They are very rare in nature, but have properties useful in the food processing industry
Saturated fats such as cholesterol are found in meat and dairy products, i.e. whole milk, cheese, butter and eggs. Many processed foods have saturated fats added to them and they are widely used in manufacturing. Unsaturated fat are found in vegetable oils like soya bean, mustard, sunflower, ground nut, olive etc and corn, peanuts, seeds, olive, oily fish etc. The fat which should be eaten in excess is the unsaturated variety which is more beneficial. An excess level of saturated fats in the blood tend to raise the level of cholesterol contributing to hardening of the arteries causing strokes and various forms of heart diseases. It is advisable to limit fat intake to no more than 30% of the overall diet. Good sources of essential fatty acids are most vegetables, nuts/seeds and marine oils,[2] including: fish, flax seed oils, soy beans, pumpkin seeds, sunflower seeds, and walnuts.

Fiber
Calories/gram: < 4
Fibre is derived from plants and is found in fruit, green leafy and root vegetables, whole meal flour and bread, bran rich food, brown rice, cereals including oats, beans and pulses. Whole grains, fruits (especially plums, prunes, and figs), and vegetables are rich in dietary fiber. Fibre plays a vital role in the digestive process by softening the bile wastes and speeding up the process of elimination of undigested food thus helping to prevent constipation. The presence of fibre regulates the absorption of fats and glucose into the bloodstream.
A high fibre diet protects against cancer. High fiber food includes wheat bran, kidney beans, potatoes, whole wheat, whole grains, legumes, whole grain bread, prunes etc. Eating beans regularly and brown rice, brown bread etc. instead of white bread and rice can meet the fibre requirements you need. Insufficient consumption of fibre may lead to the development of Colon cancer and increase levels blood cholesterol. Fiber, especially that in whole grains, may help lessen insulin spikes and reduce the risk of diabetes
It is recommended that at least five portions(25gms fibre) of vegetables and fruit should be eaten each day to provide necessary vitamins, minerals and fibre. Increase your fibre intake gradually and as you increase your fibre intake make sure that you increase your fluid intake as well.