The Glycemic Index
The Glycemic Index (GI) is a means of assessing and clarifying the blood glucose response to carbohydrate foods. It compares the blood glucose levels and the rate of carbohydrate digestion into the system. Foods are given a rating of 1 (lowest) to 100 (highest). The lower the GI of the food, the slower but more sustained is the blood sugar response. Because of this slow release of energy Low GI foods keep you feeling full longer and you get fewer cravings. Foods that are digested rapidly (causing a rapid but short term release of energy) have a high GI rating which causes the dreaded insulin response (explained below).
The following info isn’t really that essential but it explains why low GI foods are good for fat loss. If you want you can skip over this part.
When you consume high GI foods you experience a sudden increase in your blood glucose levels, which trigger the insulin response. The pancreas releases heaps of insulin with the aim of reducing the blood glucose levels. Before I go on there are two enzymes and their functions you must understand.
Lipoprotein lipase (LPL) is an enzyme that takes free fatty acids from the blood and stores it in the fat cells as triglycerides. This is called lipogenesis, the making of fat. It expands the size of fat cells by filling them up.
Hormone Sensitive Lipase (HSL) is an enzyme responsible for the release of fat from the fat cells and back into the blood stream making it available to the body for energy. This process is known as lipolysis. It reduces the size of the fat cells as the fat is being released.
Now, when insulin is released into the blood stream it increases the action of LPL (lipogenesis) in the fat cells and suppresses the action of HSL (lipolysis). So when you eat foods high in sugar, your blood glucose levels rise and the pancreas releases insulin. The insulin increases the process of lipogenesis, which means more fat is being stored in fat cells instead of being used for energy. Its even worse eating high sugar and high fat foods at the same time because the sugar increases the insulin response and the fat in the blood stream goes straight to the fat cells.
So to lose fat we must increase the use of HSL (lipolysis), which will speed up the breakdown of fat in the cells and cause it to be used as energy. Adrenaline and Cortisol enhance HSL production and are produced in response to stress. Physical stress in the form of exercise increases the rate of fat breakdown and uses the resultant free fatty acids to power muscles. Emotional stress also increases the rate of fat breakdown, however, fat stays in the bloodstream putting you at risk for artery disease. Stimulant drugs like caffeine and amphetamines also increase the above hormone production.
So, successful fat loss is dependant on maintaining blood sugar levels during the day, thereby reducing the negative effects of the insulin response. This state is produced by eating Low GI foods, preventing peaks and troughs in blood glucose levels and therefore insulin levels.
For more info about the Glycemic Index, check out this website.
http://www.glycemicindex.com/
Fats
Fats are very important in our diet as they provide a valuable source of stored energy, contain essential fatty acids, contain vitamins A, E, D and K and they are vital in many cell processes.
Fat can be classified as either:
Saturated Fats
Unsaturated Fats
Saturated Fats are found mainly in animal foods (milk, cheese, meats etc). Saturated fats contain a substance called cholesterol (a solid waxy substance). If cholesterol levels become high, blood vessels may become narrowed which in turn may lead to cardio-vascular problems. There are two types of cholesterol found in the body:
High density lipoproteins (HDL) – The good cholesterol.
Low density lipoproteins (LDL) – The bad cholesterol.
Unsaturated Fats fall into two categories:
Polyunsaturated fats
Mono-unsaturated
Polyunsaturated fats are found in most vegetable oils and fish (eg. corn, soybean, safflower and cottonseed oils) and contain essential fatty acids (explained later). They lower LDL levels and increase HDL levels, which is good.
Mono-unsaturated are found in olive and canola oil along with some fruits and nuts. Eg. olive oil, canola oil, peanut oil, cashews almonds, peanuts and avocados. They lower LDL levels and increase HDL levels.
Essential Fatty Acids
Essential fatty acids cannot be manufactured by the body and therefore must be obtained through the diet. They are not stored but saved for hormone like functions.
Omega 3 and Omega 6 are found in fish oils. Research on Eskimos has found a low incidence of heart disease even though their diets consist mainly of saturated fat in the form of seal and whale meat. By consuming fish, the effect of these essential fatty acids is a reduction in blood pressure, prevention of blood clot formation and decreased triglycerides in the blood.
You can also get essential fatty acids from flax oil and various supplements.
To conclude: for weight loss and optimal health, stay away from saturated fats and concentrate on mono-unsaturated fats, polyunsaturated fats and essential fatty acids. However even though these are good fats, excess consumption will still lead to fat gain.
Protein
Protein performs several very important functions for the body; it helps repair body cells and damaged tissue; it assists with the growth and reformation of new cells; it assists in the production of red and white blood cells, hormones and enzymes; it provides fuel reserve after all other energy reserves have been depleted.
It’s recommended that people undertaking fitness programs consume 1 gram of protein per pound of bodyweight per day. Any more than this can be harmful to your kidneys and other components of your digestive system. Also once your body has met its protein requirements the excess is stored as body fat.
Protein is broken down by the body’s digestive system into amino acids. There are two types of amino acids:
Essential Amino Acids (cannot be produced by the body)
Non-Essential Amino Acids (These can be produced from other amino acids in the body)
Protein can be obtained from a variety of sources:
Animal Foods – meat, poultry, eggs and dairy foods. These are high in protein and contain all of the essential amino acids required by the body.
Plant Foods – breads, cereals, grains, beans etc. These foods supply the body with protein but lack the required amino acids.
You can also obtain protein from supplements like Whey Protein that are very useful because you can meet your daily protein requirements without consuming too many animal products.
Protein for Energy
You should make sure you have enough protein in your diet because even though it does not play a major role in energy production for the body, your muscles will be broken down if protein is the only fuel left when carbos and fats supplies have been depleted.
To get your protein requirements consume a mixture of whey protein, lean meats, skinless poultry, eggs, low fat dairy products and seafood.
: Losing weight and being in shape just aren't changing things you eat for a couple weeks etc, etc, etc...its a LIFESTYLE CHANGE!You need to have a plan and schedule to follow daily, and set goals for yourself. Before you go about trying to lose weight and what not you need to figure out just how many calories a day you should be eating. I'm going to attach a file that is called nutrition for weight loss and if you are SERIOUS about losing weight, staying in shape, and feeling great, then please take the time to read it. I know people on these forums don't like to read a paragraph much less a couple pages...but deal with it
