Although excess fat in the diet is blamed for many health problems such as coronary heart disease and obesity, fats (or lipids) have a major role to play in the functioning of the human body. Fats:
- Waterproof the skin
- Insulate the body
- Provide an energy store
- Build cell membranes
- Are a major component of many hormones
- Maintain some of the major systems within the body
Added to this, the fat soluble vitamins A, D, E and K cannot be absorbed without the presence of fat in our system.
Cholesterol
Arguably the best known fat is cholesterol. Many people are concerned about cholesterol levels but know little about the role cholesterol plays in the body.
Cholesterol has many useful functions in the body. Cholesterol:
- is a steroid - the most abundant steroid in the body. From cholesterol a number of other steroid hormones are created, including progesterone, oestrogen and testosterone
- acts in the liver to produce bile acids, which are needed for the digestion of fat in the gut
- is essential for the creation of cell membranes
- is essential in the manufacture of vitamin D
On the down-side, cholesterol also accumulates on the walls of arteries, limiting the flow of blood to the heart and can contribute to heart disease - it is for this reason that people are concerned about having too much cholesterol in their bodies.
HDL Versus LDL
There are two types of cholesterol carriers:
- LDL (low-density lipoprotein) which clogs up the arteries
- HDL (high-density lipoprotein) which cleans the arteries
Obviously, people should have less of the LDL kind and more of the HDL kind. It is not the total cholesterol level that we have in our bodies that is important, but the amounts of HDL to LDL; at least 25% of total cholesterol should be HDL. Exercise tends to raise HDL in the blood; therefore an athlete may have a higher total cholesterol level, but his HDL percentage is also likely to be higher.
Controlling Cholesterol
Cholesterol is both obtained in the diet and synthesised (created) in the liver. The body has a ‘balancing system’ - if more cholesterol is obtained from the diet then the liver manufactures less of it and if less is eaten then the liver will create more. Contrary to popular belief, cholesterol we take in food does not appear to affect blood cholesterol levels. What it does do, is affect the body's ability to dispose of cholesterol because saturated fats inhibit the body's ability to deal with LDL.
Clearly it is advisable to reduce overall LDL levels, and the best way to do this naturally is by increasing the amount of soluble fibre in the diet. Soluble fibre is found in fruit and vegetables, and also is particularly high in porridge oats. Soluble fibre is relatively indigestible, so it acts like a ‘brush’ in the gut, causing cholesterol to bind to it, and effectively 'flushes it out'.
Regular exercise increases the body's production of HDL (good!) cholesterol which helps to 'mop up' the bad LDL cholesterol, so is also effective in helping to lower the body's overall LDL levels.
Of course, it is also best to reduce the amount of saturated fat (like butter, cheese and red meat) in the diet as well.
How Much Fat do We Need?
It is recommended that the average intake of fat should be 30% of total calorie intake. Of this 30%, only 10% should be from saturated fats.
For example, if you are a woman consuming approximately 2000 calories a day, 30% of this amount would be 600 calories. To get the correct amount in grams, then you have to divide this amount by 9, which makes 66 grams. Of this 66 grams, only 6.6 grams should be saturated.
Dietary fat is a double-edged sword - too much of it will make us overweight and put our health at risk. However, fat plays a vital role in our health and the function of our body; just try to stick to the correct amounts, and cut down on the saturated kind.
Donna Watmough - Donna Watmough lives in Norfolk Uk. Her life changed drastically after a horse-riding accident left her with a badly broken back, unable ...
