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Rebecca Hager
adhéré il y a il y a 9 ans
What You Need To Know ...
Dietary fats are one of the three major components or macro-nutrients of all foods.
The other two are carbohydrates and proteins.
Fats have a wide range of functions and are a necessary part of our diets. However certain fats can be very damaging to health and, indeed, too much fat in the diet is the root cause of type 2 diabetes.
What is fat?
The term fats covers a wide group of compounds that are composed of chains of fatty acids.
Generally speaking, a fatty acid consists of a straight chain of an even number of carbon atoms, with hydrogen atoms tacked on along the length of the chain and at one end of the chain. The other end of the chain will finish with a group of carbon, oxygen and hydrogen atoms.
Fatty acids are not found in nature in a free state. They are usually joined in groups of three together with glycerol (an alcohol) to form a molecule called a triglyceride.
During digestion, the body breaks down the fats we eat into fatty acids, which can then be absorbed into the blood. The bloodstream delivers the fatty acids throughout the body where they are used for various purposes including the storage of energy in the form of fat.
Your body is capable of synthesising most fatty acids internally from simpler constituents-with two main exceptions. These exceptions are alpha-linolenic acid (an omega-3 fatty acid) and linoleic acid (an omega-6 fatty acid).
These must be ingested in the food you eat, so they are known as essential fatty acids.
Types of fat
Fatty acids come in two basic types: saturated and unsaturated.
If the carbon-to-carbon bonds in the chain are all single bonds, the acid is a saturated fatty acid. You get this kind of fat from animal-based foods such as red meat, poultry, fish and dairy products. These fats, which include animal fat, butter, margarine and shortening, are solids at room temperature.
If any of the bonds are double or triple, the acid is an unsaturated fatty acid. Unsaturated fatty acids are reactive, ie they are more chemically active and bond with other compounds more easily. These fats are found mostly in plant-based foods and are liquid at room temperature, ie they are oils.
There are several sub-categories of fatty acids.
Monounsaturated fatty acids are fatty acids that have one double bond in the fatty acid chain while all the remaining carbon atoms are single-bonded. These fats are found most abundantly in red meat, whole milk products, nuts, olives and avocados. They are also found in other vegetable oils and whole-grain cereals.
By contrast, polyunsaturated fatty acids have more than one double bond. These fats are found mostly in nuts, seeds, leafy greens, algae, fish and krill (tiny shrimp-like marine creatures).
Trans-fats are unsaturated fats that have been transformed into saturated fats by reaction with hydrogen, a process called partial-hydrogenation. This may be done, for example, to turn vegetable oils into vegetable shortening, a solid that melts at 30 to 40 degrees centigrade and stores much better than polyunsaturated oils which go rancid in the presence of oxygen in the air.
Good fats and bad fats
There are 9 calories in a gram of fat, no matter which kind of fat it is, compare with protein and carbohydrates, macro-nutrients that only deliver 4 calories a gram. These calories can add up quickly, so you can gain weight easily by eating fat of any kind.
There are two individual types of dietary fat (the fat you get by eating) that are harmful: saturated fats and trans-fats.
Saturated fats raise the levels of your total blood cholesterol and your low-density lipoprotein (LDL) which can raise your risk of cardiovascular disease. These fats may also increase the risk of type 2 diabetes.
Trans-fats are considered to be very bad for your health. Many research studies have shown that these fats increase unhealthy LDL cholesterol and reduce healthy high-density lipoprotein (HDL) cholesterol, which increases the risk of cardiovascular disease significantly.
The unsaturated fats are considered to be beneficial to your health-though I have my reservations where type 2 diabetics are concerned.
Some studies suggest that monounsaturated fats improve the levels of your blood cholesterol which could reduce your risk of heart disease. Research also suggests that these fats may help insulin levels for type 1 diabetes, thus helping these diabetics to control their blood sugar.
Other studies suggest that polyunsaturated fats also improve cholesterol levels and so may reduce your risk of diseases of the coronary arteries. These fats may also reduce the risk of type 2 diabetes.
Omega-3 fatty acids, a type of polyunsaturated fat found in some fatty fishes, appears to decrease the risk of coronary artery disease. It may also protect against irregular heartbeats and help lower blood pressure. Omega-3 fatty acids can also be found in plants but the body does not use this type of Omega-3 as well as it does omega-3 from fish.
Functions of fats in your body
During digestion, dietary fats are broken down and their constituents, glycerol and fatty acids, are released. Fatty acids have many important functions in the body.
Dietary fat is a source of energy for your body. The glycerol you get along with dietary fatty acids can be converted directly into glucose by the liver. The fatty acids, however, have to go through a series of transformations before they are turned into glucose.
When you consume dietary fat, the long chains of fatty acids are broken into smaller molecules that consist of just a couple of carbon atoms. Glucose, which you need for energy, has six carbon atoms and, as fatty acids have been reduced to molecules containing less than six carbon atoms, your body cannot convert dietary fats directly into glucose.
When you eat more fat than you need for immediate use, the fats you synthesise internally from the fatty acids you have digested are stored in the form of triglycerides which contain six carbon atoms. When your body runs low on glucose to use as energy, hormones release triglycerides from the fat cells and lipase enzymes break them down for the body to use as energy.
Besides being sources of energy, dietary fats have many more vital functions. They are sources of the essential fatty acids, which are necessary for health.
Fats play a vital role in keeping skin and hair healthy, in insulating body organs against shock, in maintaining body temperature, and in promoting the healthy functioning of cells.
They are also vital for the absorption of vitamins A, D, E and K. These vitamins are fat soluble and can only be digested, transported and absorbed in conjunction with fats.
Fat also acts as a buffer against many diseases. When a foreign substance reaches unsafe levels in the bloodstream, the body can effectively dilute the substance by storing it in new fat tissue. This helps to protect vital organs until such time as the offending substance can be metabolized or removed from the body through urination, excretion, or the growth of hair.
How much fat do you need to eat?
To remain healthy, you need to concentrate on unsaturated fats and avoid saturated fats and trans-fats which are harmful to your health.
Indeed The Dietary Guidelines for Americans, 2010, produced by the US Department of Agriculture and US Department of Health and Human Services states that the human body makes more than enough saturated fats to meet its needs and does not require more from dietary sources.
These guidelines go on to recommend that you limit your total fat to 20 to 35 percent of your daily calories, ie 44 to 78 grams of total fat if you are a normal healthy man eating 2,000 calories a day. And, as you should not be eating any saturated fats, all the fats you eat in one day should be limited to monounsaturated fats, polyunsaturated fats and omega-3 fatty acids.
Calculating how much fat you can eat in grams is a cinch. All you have to do is multiply the daily total intake of calories you desire by the recommended percentage of fat intake, and then divide the result by nine (the number of calories in a gram of fat).
For example, if you eat 2,000 calories a day and want to limit your intake of fat to 20% of your daily calories, multiply 2,000 by 20% to get 400 calories. Then divide the 400 by 9 (calories per gram) to get 44.4 grams of total fat a day.
The problem with these dietary guidelines is that they are designed for people who are healthy. You are a type 2 diabetic so you are not healthy. In fact, you have an insidious disease that will destroy your health unless you can control it.
The core problem in type 2 diabetes is that fat is blocking the receptors in your muscle cells, thereby preventing insulin from doing its job of getting glucose (produced by your digestion) into the cells to fuel your muscles.
The only way to clear the receptors is to stop ingesting fat. If you can do this, you will find that after three or four weeks your blood glucose is under control and your insulin is functioning normally.
Thus, the key to reversing your type 2 diabetes-ie to return you blood glucose levels to their pre-diabetes levels-is to eliminate fat from you diet as far as possible.
You diet, of course, must also be low in sugar and salt, high in fibre and digested slowly. In addition, it must exclude eggs and all dairy products, and you must drink plenty of water.
It is obvious that you cannot minimise the fat you ingest by following the Dietary Guidelines for Americans.
What you need to do, in fact, is to make sure that a serving of food contains only a maximum of 2 grams of fat and that only 10% of the energy it delivers (total calories) comes from fat. You can see this from the labels.
Foods to eat and foods to avoid
You need to be aware that many foods contain different kinds of fat and varying levels of each type.
Butter, for example, contains unsaturated fats, but a large percentage of the total fat in butter is saturated fat. And, while canola oil contains a high percentage of monounsaturated fat, it also comes with smaller amounts of polyunsaturated and saturated fat.
However, saturated fats come mainly from animal products, meat, fish and dairy products such as milk, cream, butter and yoghurt, while trans-fats are manufactured by the food industry.
Major sources of unsaturated fats (‘good’ fats) include nuts, olives, avocados, seeds, leafy greens vegetables, algae, fish and krill. You get omega-3 fatty acids in fish and vegetables.
To successfully reverse type 2 diabetes you need to eat food that, among other things, is low in fat. In fact, you need to minimise the fat in your diet as far as possible. You can do this by choosing foods that are low in fat. These foods are mainly vegetables so the diet you follow must be plant-focused.
Thus, you should only eat a little meat and then only the leanest of cuts. Once cooked, you should cut away all visible fat (on the edge of steaks, say). As regards chicken, limit yourself to the white meat (breast) only and make sure that the skin has been stripped off before you put it in your mouth.
Fish you can eat for the omega-3 fatty acids but only small amounts twice a week and again the skin should be stripped off before you eat it.
Most of the food you eat should consist of plants or be based on plants. Vegetables, whole grains, fruits and so one will give you all the fatty acids you need including the two essential ones. You don’t really need animal products, though a little ultra-lean meat and fish will do no harm.
It’s almost impossible to avoid processed foods entirely, though most of them are outside the limits imposed by a low-fat, low-sugar and low-salt diet. However there are some foods that fit the bill. But you have to learn to read and understand food labelling so you can be sure that what you buy does not breach the guidelines for your diet.
I’ll let you into a little secret: a plant-based diet, once you get into it, can taste absolutely delicious.
Bonjour tout le monde !